WO2020257784A1

WO2020257784A1 - Inspection risk estimation using historical inspection data

Info

Publication number: WO2020257784A1
Application number: PCT/US2020/038988
Authority: WO
Inventors: Binh Thanh Nguyen; Viet Cuong Thanh Nguyen
Original assignee: Inspectorio Inc.
Priority date: 2019-06-21
Filing date: 2020-06-22
Publication date: 2020-12-24
Also published as: CN112116185A; CA3050952A1

Abstract

Inspection risk estimation using historical inspection data is provided. In various embodiments, attributes of a future inspection of a factory and historical data related to the future inspection are received. A plurality of features are extracted from the attributes of the future inspection and the historical data. The plurality of features are provided to a trained classifier. A risk score indicative of a probability of failure of the future inspection is obtained from the trained classifier.

Description

INSPECTION RISK ESTIMATION USING HISTORICAL INSPECTION DATA

BACKGROUND

[0001 ] Embodiments of the present disclosure relate to inspection risk estimation, and more specifically, to inspection risk estimation using historical inspection data.

BRIEF SUMMARY

[0002] According to embodiments of the present disclosure, methods of and computer program products for inspection risk estimation are provided. In various embodiments, attributes of a future inspection of a factory and historical data related to the future inspection are received. A plurality of features are extracted from the attributes of the future inspection and the historical data. The plurality of features are provided to a trained classifier. A risk score indicative of a probability of failure of the future inspection is obtained from the trained classifier.

[0003] In various embodiments, the historical data are preprocessed. In various

embodiments, preprocessing the data comprises aggregating the historical data. In various embodiments, preprocessing the data further comprises filtering the data.

[0004] In various embodiments, the data further comprise performance history of the factory. In various embodiments, the data further comprise geographic information of the factory. In various embodiments, the data further comprise ground truth risk scores. In various embodiments, the data further comprise product data of the factory. In various embodiments, the data span a predetermined time window.

[0005] In various embodiments, providing the plurality of features to the trained classifier comprises sending the plurality of features to a remote risk prediction server, and

obtaining from the trained classifier a risk score comprises receiving a risk score from the risk prediction server.

[0006] In various embodiments, extracting the plurality of features comprises removing features with a low correlation to a target variable. In various embodiments, extracting the plurality of features comprises applying a dimensionality reduction algorithm. In various embodiments, extracting a plurality of features from the data comprises applying an artificial neural network. In various embodiments, applying the artificial neural network comprises receiving a first feature vector as input, and outputting a second feature vector, the second feature vector having a lower dimensionality than the first feature vector. [0007] In various embodiments, the risk score is provided to a user. In various embodiments, providing the risk score to the user comprises sending the risk score to a mobile or web application. In various embodiments, said sending is performed via a wide area network.

[0008] In various embodiments, the trained classifier comprises an artificial neural network.

In various embodiments, the trained classifier comprises a support vector machine. In various embodiments, obtaining from the trained classifier a risk score comprises applying a gradient boosting algorithm.

[0009] In various embodiments, the risk score is related to the probability by a linear mapping.

[0010] In various embodiments, the performance of the trained classifier is measured by comparing the risk score to a ground truth risk score, and parameters of the trained classifier are optimized according to the performance. In various embodiments, optimizing the

parameters of the trained classifier comprises modifying hyperparameters of a trained machine learning model. In various embodiments, optimizing the parameters of the trained classifier comprises replacing a first machine learning algorithm with a second machine learning algorithm, the second machine learning algorithm comprising hyperparameters configured to improve the performance of the trained classifier.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0011 ] Fig. 1 is a schematic view of an exemplary system for inspection risk estimation according to embodiments of the present disclosure.

[0012] Fig. 2 illustrates a process for inspection risk estimation according to embodiments of the present disclosure.

[0013] Fig. 3 illustrates a process for training an inspection risk estimation system according to embodiments of the present disclosure.

[0014] Fig. 4 illustrates a process for updating an inspection risk estimation system according to embodiments of the present disclosure.

[0015] Fig. 5 illustrates a process for training an inspection risk estimation system according to embodiments of the present disclosure.

[0016] Fig. 6 illustrates a process for training an inspection risk estimation system according to embodiments of the present disclosure.

[0017] Fig. 7 illustrates a process for training an inspection risk estimation system according to embodiments of the present disclosure. [0018] Fig. 8 depicts a computing node according to embodiments of the present disclosure.

DETAILED DESCRIPTION

[0019] Inspections commonly occur in factories in order to ensure quality control and adherence

to protocol. Estimating the risk of failing a particular inspection in advance of the inspection date allows factories and their business partners the ability to implement a dynamic quality control program based on the estimated risk.

[0020] The present disclosure provides a framework for estimating the risk of failure of an inspection, prior to the inspection date, using historical inspection data and machine learning methods.

[0021 ] In embodiments of the present disclosure, inspection risk estimation is performed by obtaining data related to an inspection, extracting a plurality of features from the data, providing the features to a trained classifier, and obtaining from the trained classifier a risk score indicative of the probability that the inspection is likely to pass or fail. In some embodiments, a feature vector is generated and inputted into the trained classifier, which in some embodiments comprises a machine learning model.

[0022] In embodiments of the present disclosure, data may be obtained in a variety of formats. Data may be structured or unstructured, and may comprise information stored in a plurality of media. Data may be inputted manually into a computer, or may be obtained automatically from a file via a computer. It will be appreciated that a variety of methods are known for obtaining data via a computer, including, but not limited to, parsing written documents or text files using optical character recognition, text parsing techniques (e.g., finding key/value pairs using regular expressions), and/or natural language processing, scraping web pages, and/or obtaining values for various measurements from a database (e.g., a relational database), XML file, CSV file, or JS ON object.

[0023] In some embodiments, factory or inspection data may be obtained directly from an inspection management system, or other system comprising a database. In some

embodiments, the inspection management system is configured to store information related to factories and/or inspections. The inspection management system may collect and store various types of information related to factories and inspections, such as information pertaining to purchase orders, inspection bookings, assignments, reports, corrective and preventive action (CAPA), inspection results, and other data obtained during inspections. It will be appreciated that a large set of data may be available, and in some embodiments, only a subset of the available data is used for input into a prediction model. The subset of data may contain a sufficient number of attributes to successfully predict inspection results.

[0024] As used herein, an inspection booking refers to a request for a future inspection to take place at a proposed date. The inspection booking may be initiated by a vendor, brand, or retailer, and may contain information of a purchase order corresponding to the future inspection. As used herein, an assignment refers to a confirmed inspection booking. The assignment may contain a confirmation of the proposed date of the inspection booking, as well as an identification of an assigned inspector and information related to the booking.

[0025] Data may be obtained via a data pipeline that collects data from various sources of factory and inspection data. A data pipeline may be implemented via an Application

Programming Interface (API) with permission to access and obtain desired data and calculate various features of the data. The API may be internally facing, e.g., it may provide access to internal databases containing factory or inspection data, or externally facing, e.g., it may provide access to factory or inspection data from external brands, retailers, or factories. In some embodiments, data are provided by entities wishing to obtain a prediction result from a prediction model. The data provided may be input into the model in order to obtain a prediction result, and may also be stored to train and test various prediction models.

[0026] The factory and inspection data may also be aggregated and statistical analysis may be performed on the data. According to embodiments of the present disclosure, data may be aggregated and analyzed in a variety of ways, including, but not limited to, adding the values for a given measurement over a given time window (e.g., 7 days, 14 days, 30 days, 60 days, 90 days, 180 days, or a year), obtaining the maximum and minimum values, mean, median, and mode for a distribution of values for a given measurement over a given time window, and obtaining measures of the prevalence of certain values or value ranges among the data. For any feature or measurement of the data, one can also measure the variance, standard deviation, skewness, kurtosis, hyperskewness, hypertailedness, and various percentile values (e.g., 5%, 10%, 25%, 50%, 75%, 90%, 95%, 99%) of the distribution of the feature or measurement over a given time window.

[0027] The data may also be filtered prior to aggregating or performing statistical or

aggregated analyses. Data may be aggregated by certain characteristics, and statistical analysis may be performed on the subset of data bearing the characteristics. For example, the above metrics can be calculated for data related only to inspections that passed or failed, related to during product (DUPRO) inspections, or to inspections of above a minimum sample size.

[0028] Aggregation and statistical analysis may also be performed on data resulting from prior aggregation or statistical analysis. For example, the statistical values of a given measurement over a given time period may be measured over a number of consecutive time windows, and the resulting values may be analyzed to obtain values regarding their variation over time. For example, the average inspection fail rate of a factory may be calculated for various consecutive 7-day windows, and the change in the average fail rate may be measured over the 7-day windows.

[0029] In embodiments of the present disclosure, inspection data include information correlated with the results of the inspection (e.g., whether the inspection was passed or not). Examples of suitable data for predicting the outcome of an inspection include: data obtained from previous inspections at the same factory at which the future inspection is to take place, data obtained from inspections at other factories, data obtained from

inspections at other factories with similar products or product lines to the subjects of the future inspections, data obtained from the factory across multiple inspections, attributes of future inspection bookings (e.g., the geographic location, time, entity performing the inspection, and/or the type of inspection), data related to the business operations of the factory, data related to product quality of the factory, general information regarding the factory, data related to the sustainability of the factory or other similar factories, and/or data related to the performance of the factory or other similar factories. The data may comprise the results of past inspections (e.g., whether the inspection was passed or not). The data may comprise information obtained from customer reviews on products or product lines similar to those produced by the factory, and/or customer reviews on products or product lines originating at the factory. It will be appreciated that for some metrics, a factory may be divided into various divisions within the factory, with different metrics obtained for each division.

[0030] Examples of data related to future inspection include: the number of orders placed at the factory, the quantity of the orders, the quality of the orders, the monetary value of the orders, general information regarding the orders, the description of each product at the factory, (e.g., the product's stock keeping unit (SKU), size, style, color, quantity, and packaging method), the financial performance of the factory, the number of inspected items at the factory, the number of inspected items at the factory during inspections of procedures such as workmanship, packaging, and measurement, information regarding the acceptable quality limit (AQL) of processes at the factory (e.g., the sampling number used to test quality), the inspection results of past inspections at the factory, the inspection results of past

inspections for the product/product line, the inspection results at other factories with similar products, the inspection results of past inspections at business partners of the factory, the values for various metrics collected over the course of inspections, the geographic location of the factory, the factory's size, the factory's working conditions and hours of operation, the time and date of the inspection, the inspection agency, the individual agents performing the inspection, and aggregations and statistical metrics of the aforementioned data.

[0031] As used herein, a product or product line's style refers to a distinctive appearance of an item based a corresponding design. A style may have a unique identification (ID) within a particular brand, retailer, or factory. Style IDs may be used as an identifying feature by which other measurements may be aggregated in order to extract meaningful features related to inspection results and risk calculation.

[0032] It will be appreciated that a large number of features may be extracted by a variety of methods, such as manual feature extraction, whereby features with a significant correlation to the target variable (e.g., the results of the future inspection) are calculated or extracted from the obtained data. A feature may be extracted directly from the data, or may require processing and/or further calculation to be formatted in such a way that the desired metric may be extracted. For example, given the results of various inspections at a factory over the last year, one may wish to calculate the percentage of failed inspections over the time period. In some embodiments, extracting features results in a feature vector, which may be preprocessed by applying dimensionality reduction algorithms (such as principal component analysis and linear discriminant analysis) or inputting the feature vector into a neural network, thereby reducing the vector's size and improving the performance of the overall system.

[0033] In some embodiments, the trained classifier is a random decision forest. However, it will be appreciated that a variety of other classifiers are suitable for use according to the present disclosure, including linear classifiers, support vector machines (SVM), gradient boosting classifiers, or neural networks such as convolutional neural networks (CNN) or recurrent neural networks (RNN).

[0034] Suitable artificial neural networks include but are not limited to a feedforward neural network, a radial basis function network, a self-organizing map, learning vector quantization, a recurrent neural network, a Hopfield network, a Boltzmann machine, an echo state network, long short term memory, a bi-directional recurrent neural network, a hierarchical recurrent neural network, a stochastic neural network, a modular neural network, an associative neural network, a deep neural network, a deep belief network, a convolutional neural networks, a convolutional deep belief network, a large memory storage and retrieval neural network, a deep Boltzmann machine, a deep stacking network, a tensor deep stacking network, a spike and slab restricted Boltzmann machine, a compound hierarchical-deep model, a deep coding network, a multilayer kernel machine, or a deep Q-network.

[0035] In some embodiments, an estimated risk score comprises a value in a specified range, e.g., a value in the range [0,100]. For example, a future inspection at a factory with perfect performance that has never failed an inspection may achieve a score of 0, indicating that it is almost certain to pass, while a future inspection at a factory with poor performance that has failed every inspection may achieve a score of 100, indicating that it will almost certainly fail. In some embodiments, the estimated risk score may be compared against a threshold value, and a binary value may be generated, indicating whether the inspection is likely to pass or not (e.g., 0 if the score is below the threshold, and 1 otherwise). The threshold may be chosen heuristically, or may be adaptively calculated during the training of the machine learning model. In some embodiments, determining the risk score is

transformed into a binary classification problem.

[0036] The performance of machine learning models according to embodiments of the present disclosure may be tested against new data, and the machine learning model may be updated in order to improve its performance. In some embodiments, updating the machine learning model comprises modifying hyperparameters of the model. In some embodiments, updating the machine learning model comprises using a different machine learning method than the one currently used in the model, and modifying the hyperparameters of the different machine learning method in order to achieve a desired performance.

[0037] In embodiments of the present disclosure, historical inspection data from a number of inspections during a given time window are used in estimating the risk of failing a particular inspection. It will be appreciated that a variety of time windows may be used, e.g., three months, six months, nine months, or a year. In some embodiments, the estimation may be updated at a regular frequency, e.g., every week, every two weeks, or every month.

Obtaining updated risk estimations of inspections will assist retailers and manufacturers in reducing their potential risk when anticipating an inspection.

[0038] In some embodiments, the predicted risk results are converted to a binary

output indicating whether the inspection is likely to pass or fail.

[0039] In embodiments of the present disclosure, a machine learning model comprising a classifier is trained by assembling a training dataset comprising historical data of inspections during a variety of time windows, and corresponding performance results for these inspections over their respective time windows. In some embodiments, the inspection data further comprise data related to the factories in which the inspection took place, such as data related to previous inspections at the factory, the performance of the factory, or general information related to the factory, as discussed above. In some embodiments, inspections are assigned a label indicating whether they are likely to pass or to fail. An initial training dataset is generated from the collected data, to which machine learning techniques may be applied to generate an optimal model for predicting inspection risk. It will be appreciated that inspection risk prediction may be transformed into a binary classification problem, where a given inspection is classified as being likely to either pass or fail.

[0040] In some embodiments, training the machine learning model comprises extracting features from the initial training dataset. In some embodiments, the selected features to be extracted have a high correlation to a target variable. In some embodiments, the number of features is reduced in order to reduce the calculation cost in training and deploying the risk estimation model. In some embodiments, a number of machine learning methods and classification approaches are tested on the training dataset, and a model with the most desired performance is chosen for deployment in the risk estimation model. It will be appreciated that a variety of machine learning algorithms may be used for risk assessment, including logistic regression models, random forest, support vector machines (SVM), deep neural networks, or boosting methods, (e.g., gradient boosting, Catboost). The

hyperparameters of each model may be learned to achieve a desired performance. For example, in some embodiments, the Institute of Data Science of Technologies (iDST) framework may be used for hyperparameter tuning. It will be appreciated that the performance of a machine learning model may be measured by different metrics. In some embodiments, the metrics used to measure the machine learning model's performance comprise accuracy, precision, recall, AUC, and/or FI score.

[0041 ] In embodiments of the present disclosure, the hyperparameters for various machine learning risk estimation models are learned, and the performance of each model is measured. In some embodiments, the metrics used to measure the machine learning model's performance comprise accuracy, precision, recall, AUC, and/or FI score. In some embodiments, the initial dataset is divided into three subsets: a training dataset, a validation dataset, and a testing dataset. [0042] In some embodiments, 60% of the initial dataset is used for the training dataset,

20% is used for the validation dataset, and the remaining 20% is used for the testing dataset. In some embodiments, cross validation techniques are used to estimate the performance of each risk estimation model. Performance results may be validated by subjecting the selected risk prediction model to new inspection data.

[0043] It will be appreciated that predicting the risk of failing an inspection is useful in achieving dynamic, risk-based quality control. For example, given the risk of a particular inspection, a specific inspection workflow or template may be automatically generated based on the requirements of either the factory or a business partner of the factory. The calculated risk may be applied to the critical path or time and action plan of a style or purchase order in order to modify the number of inspections required. Based on the calculated level of risk of a particular inspection, an inspection team may assess whether they should waive or confirm an inspection booking. Estimated risk may also be leveraged to make determinations as to the nature of inspections. For example, for an inspection with a high risk of failure, the inspection might be performed via an internal, independent team, while a low risk inspection might have the personnel responsible for the performance of the factory performing the inspections themselves.

[0044] Referring now to Fig. 1 , a schematic view of an exemplary system for inspection risk estimation according to embodiments of the present disclosure is shown. Inspection booking ID 102 is provided, and relevant features 104 are extracted from inspection database 1 12 comprising historical inspection data. The extracted features may be represented by a feature vector. The feature vector may be pre-processed prior to being input into inspection risk prediction server 106. An estimated prediction result 108 is obtained. In some embodiments, pre-processing the feature vector comprises applying a dimensionality reduction technique to the vector, such as principal component analysis or linear discriminant analysis. The estimated prediction result may comprise a binary value indicating whether the inspection is likely to pass or fail. In some embodiments, the estimated prediction result comprises a value in a specified range, e.g., a value in the range [0,100]. Relevant features 104 may be obtained from a factory, from inspection database 1 12, or from any combination of sources. The relevant features may comprise data related to inspections at a factory in which the future inspection is to take place, data related to the performance of the factory, data related to the factory in general, data relating to a product being inspected, or data related to the inspection booking, as discussed above. The relevant features may also be specific to the type of product the inspection will be conducted for, or the specific product line of the product. In some embodiments, estimated prediction result 108 is sent to mobile or web application 1 10, where it may be used for further analysis or decision making. The mobile application may be implemented on a smartphone, tablet, or other mobile device, and may run on a variety of operating systems, e.g., iOS, Android, or Windows. In various embodiments, estimated prediction result 108 is sent to mobile or web application 1 10 via a wide area network.

[0045] Referring now to Fig. 2, a process for inspection risk estimation according to embodiments of the present disclosure is shown. Inspection booking 201 is input into inspection risk prediction system 202 to obtain predicted inspection result 206. In some embodiments, inspection risk prediction system 202 employs a machine learning model to estimate the risk of failure associated with an inspection. In some embodiments, inspection risk prediction system 202 is deployed on a server. In some embodiments, the server is a remote server. In some embodiments, inspection risk estimation process 200 comprises performing data processing step 203 to collect and process data related to inspection booking

201 . Data processing may comprise various forms of aggregating the data, obtaining statistical metrics of the data, and formatting the data in such a way that features can be extracted from them. In some embodiments, the data are obtained from a variety of sources. In some embodiments, process 200 comprises performing feature extraction step 204 on the collected data to extract various features. In some embodiments, feature extraction step 204 is performed on data that has been processed at step 203. In some embodiments, a feature vector is output. In some embodiments, the features extracted at 204 are input into a trained classifier at 205. In some embodiments, the classifier comprises a trained machine learning model. In some embodiments, the classifier outputs prediction results 206. In some embodiments, steps 203, 204, and 205 are performed by inspection risk prediction system

202. The steps of process 200 may be performed locally to the inspection site, may be performed by a remote server, e.g., a cloud server, or may be shared among a local computation device and a remote server. In some embodiments, prediction results 206 comprise a binary value indicating whether or not the inspection is likely to be failed.

[0046] Referring now to Fig. 3, a process for training an inspection risk estimation system according to embodiments of the present disclosure is shown. The steps of process 300 may be performed to train an inspection risk estimation model. In some embodiments, the model is deployed on a prediction server. The steps of process 300 may be performed locally to the factory site, may be performed by a remote server, e.g., a cloud server, or may be shared among a local computation device and a remote server. At 302, an initial training dataset is created. In some embodiments, the training dataset may comprise data of a large number of past inspections from a number of factories, as well as the results of the inspections (e.g., pass or fail). The dataset may comprise data related to the factory at which the inspection took place and/or the product or product line for which the inspection took place, and may comprise various values corresponding to various measurements made over the course of previous inspections. In some embodiments, inspection data and corresponding inspection results are timestamped. In some embodiments, the data obtained may be aggregated over a given length of time or number of inspections. In some embodiments, the data obtained is collected only from inspections during a given time window. In some embodiments, a list of factories and inspection results may be obtained, with inspection results as labels for the inspection data.

[0047] At 304, the inspection risk prediction is formulated as a binary classification problem wherein a given inspection is classified as either predicted to pass or predicted to fail. In some embodiments, a label of 1 is assigned to an inspection if it is predicted to pass, and a label of 0 is assigned if the inspection is predicted to fail.

[0048] Useful features are then extracted from the initial training dataset. The extracted features may correspond to different time windows, e.g., three months, six months, nine months, or a year. The importance of each feature in estimating a final risk result for an inspection is calculated. In some embodiments, the importance of each feature is calculated by measuring the feature's correlation with the target label (e.g., the inspection result). At 306, a number of machine learning models are trained on the training dataset, and the performance of each model is evaluated. It will be appreciated that acceptable machine learning models include a Catboost classifier, a neural network (e.g., a neural network with 4 fully-connected hidden layers and a ReLU activation function), a decision tree, extreme boosting machines, random forest classifier, SVM, and logistic regression, in addition to those described above. The hyperparameters of each model may be tuned so as to optimize the performance of the model. In some embodiments, the metrics used to measure the machine learning model's performance comprise accuracy, precision, recall, AUC, or FI score. The most useful features for performing the desired estimation are selected. At 308, the performance of the machine learning models are compared. The model with the most desired performance is chosen at 310. In some embodiments, a final list of features used in the prediction calculation is outputted. At 312, the chosen model is deployed onto a prediction server. [0049] Referring now to Fig. 4, a process for updating an inspection risk estimation system according to embodiments of the present disclosure is shown. In some embodiments of process 400, an existing inspection risk prediction model is updated. In some embodiments, updating the prediction model comprises inputting new data and modifying the parameters of the learning system accordingly to improve the performance of the system. In some embodiments, a new machine learning model may be chosen to perform the estimation. The inspection risk prediction model may be updated at regular intervals, e.g., monthly, bimonthly, or quarterly, or may be updated when a certain amount of new data are accumulated. It will be appreciated that an updated risk estimation system provides for more accurate risk estimation compared to existing methods.

[0050] In some embodiments, new data and inspection results 420 for a number of inspections are collected from inspection management platform 410 and used to generate a new dataset with labels corresponding to the data for each inspection. Inspection management platform 410 may comprise a database containing inspection data and inspection results for a number of past inspections. New data and inspection results 420 may comprise customer feedback regarding prior predictions, and may include ground truth risk scores comprising indications of the accuracy of prior predictions, such as which predictions made by the prediction model were incorrect, as well as corrected results for the predictions. It will be appreciated that the new dataset may be structured in a similar way to the initial dataset described above. In some embodiments, the new dataset is combined with an existing training dataset 430 to create a new training dataset 440. In some embodiments, the performance of the latest version of the trained risk prediction model 499, comprising inspection risk predictor 450, is measured on the new training dataset. In some embodiments, if the performance of the latest version of the trained risk prediction model 499 and predictor 450 is under a certain threshold, feature re-engineering step 460 and/or applying new machine learning models 480 may be performed at 470 to retrain the prediction model. The threshold may be chosen heuristically, or may be adaptively calculated during training.

[0051] It will be appreciated that the methods of re-training the prediction model at 470 may be similar to those used in training the inspection risk estimation system, as described above. The process of re-training the prediction model may be repeated a number of times until the performance of the model on the new training dataset reaches an acceptable threshold. In some embodiments, the latest version of the trained risk prediction model 499 is updated at 490 with the new model trained at 470. The updated risk prediction model may then be deployed on prediction server 495. Existing training dataset 430 may also be updated to reflect the newly obtained data.

[0052] Referring now to Figs. 5-7, various processes for training inspection risk estimation systems according to embodiments of the present disclosure are shown. In various embodiments of the present disclosure, generating a trained risk estimation system comprises four primary steps: data collection, feature extraction, model training, and risk prediction. In some embodiments, data collection comprises creating an initial training dataset using the methods described above. In some embodiments, feature extraction comprises extracting a number of useful features from the initial training dataset. The features extracted may be a subset of a larger number of features that may be extracted from the initial training dataset. In some embodiments, the importance of each feature to the risk prediction calculation is measured. In some embodiments, the features with the least relevance to the prediction calculation are not used in the risk prediction model. In some embodiments, a fixed number of features are extracted. In some embodiments, determining the relevance of a feature to the prediction calculation comprises measuring the correlation of the feature with the risk prediction results. In some embodiments, a dimensionality reduction technique (e.g., principal component analysis or linear discriminant analysis) may be applied to the extracted features. In some embodiments, the feature extraction step comprises manual feature extraction. Model training comprises measuring the performance of a number of machine learning models on the extracted features. The model with the most desired performance may be selected to perform risk prediction. [0053] Referring now to Fig. 5, a process for training an inspection risk estimation system according to embodiments of the present disclosure is shown. In some embodiments, manual feature extraction 502 is performed on an initial training dataset 501 comprising data related to an inspection booking. Features may be extracted based on inspection data during a specific time window (e.g., one year). In some embodiments, a feature vector corresponding to each inspection's data are generated from the feature extraction step. In some embodiments, a label is assigned to each feature vector. In some embodiments, the labels are obtained from the initial training dataset 501 . In some embodiments, the label is a binary value indicating whether the inspection passed or failed. In some embodiments, the risk estimation of an inspection is transformed into a binary classification problem, wherein an inspection can be classified as passing or failing. Various machine learning models (e.g., support vector machine, decision tree, random forest, or neural networks) and boosting methods (e.g., Catboost or XGBoost) may be tested at 503 on the initial training dataset. [0054] In training the various machine learning models and boosting methods, the initial training dataset may be divided into a training dataset and a testing dataset. For example, 80% of the initial training dataset may be used to create a training dataset, and the remaining 20% may be used to form a testing dataset. In some embodiments, the initial training dataset may be divided into a training dataset, a testing dataset, and a validation dataset. In some embodiments, the hyper-parameters of the machine learning models and boosting methods are tuned to achieve the most desired performance. The model with the most desired performance may then be selected to provide risk estimation on input inspection data. In some embodiments, the selected model is deployed onto a prediction server to providing for future risk predictions.

[0055] In some embodiments of the present disclosure, a feature vector is calculated from inspection data. The feature vector is input into a risk prediction model and a predicted failure probability is outputted. The probability may be compared with a given threshold to determine whether the inspection should be classified as passing or not. In some embodiments, an inspection is considered likely to pass if the predicted probability is greater than or equal to the threshold. In some embodiments, a risk score is obtained based on the calculated probability. In some embodiments, the risk score comprises a value in a predetermined range, e.g., [0, 100]. In some embodiments, testing the risk prediction model comprises comparing the predicted inspection results with known data.

[0056] In some embodiments, a risk score R is obtained based on the calculated probability p using the following procedure:

[0057] A range [A, B] defining the upper and lower bounds of the risk score is chosen. For example, one may consider the risk score R to be within the range [0, 100], where R = 0 represents a lowest possible risk of an inspection (e.g., the inspection is almost certain to pass), and R = 100 represents a highest possible risk of an inspection (e.g., the inspection is almost certain to fail). Given that the predicted probability p is within the unit interval [1 , 0], one can determine a mapping Fto assign a predicted probability to a corresponding risk score R:

F: [0,1]— > [A, B]

Equation 1

[0058] For a given p,

[0059] F is chosen such that F(0) = A and F(1 ) = B. For example, a linear mapping may be used:

F(p) = A x p + (Ί — pj x S

Equation 3

[0060] Referring now to Fig. 6, a process for training an inspection risk estimation system according to embodiments of the present disclosure is shown. In some embodiments, features are obtained from inspection data 601 using manual feature extraction 602. It will be appreciated that feature extraction may result in a large number of extracted features for each inspection, and thus, large feature vectors. The number of features extracted may number in the hundreds. Reducing the dimensionality of the feature vectors may result in more efficient training, deployment, and operation of the prediction model. In some embodiments, the dimensionality of a feature vector is reduced at 603 by calculating the correlation of each feature to the target variable, and only keeping those features with high correlation to the target variable. In some embodiments, the dimensionality of a feature vector is reduced at 603 by applying a dimensionality reduction algorithm to the vector, such as principal component analysis (PCA) or linear discriminant analysis (LDA). In some embodiments, the features computed in the resulting smaller-dimension vectors for a number of inspections are input into various machine learning and/or gradient boosting models at 604, and the model with the most desired performance is selected, as described above.

[0061 ] Referring now to Fig. 7, a process for training an inspection risk estimation system according to embodiments of the present disclosure is shown. In some embodiments, features are obtained from inspection data 701 using manual feature extraction 702. In some embodiments, the feature extraction step results in a feature vector. In some embodiments, the feature vector is input into a neural network at 703. In some

embodiments, the neural network comprises a deep neural network. In some embodiments, the neural network comprises an input layer, a number of fully-connected hidden layers, and an output later with a predetermined activation function. In some embodiments, the activation function comprises a ReLU or sigmoid activation function, although it will be appreciated that a variety of activation functions may be suitable. The output of the neural network may be considered as a new feature vector, and may be input into various machine learning models at 704 using similar steps to those described above. In some embodiments, the new feature vector is of smaller dimensionality than the input feature vector. [0062] Table 1 lists a number of features that may be extracted from inspection data using the methods described above. In various exemplary embodiments, gradient boosting on decision trees is applied, for example using catboost. These features may have high correlation with the target variable. Note that features marked with an asterisk (^*) may be computed right after an inspection booking is confirmed and becomes an assignment.

Table 1

[0063] It will be appreciated that a variety of additional features and statistical measures may be used in accordance with the present disclosure.

[0064] Referring now to Fig. 8, a schematic of an example of a computing node is shown. Computing node 10 is only one example of a suitable computing node and is not intended to suggest any limitation as to the scope of use or functionality of embodiments described herein. Regardless, computing node 10 is capable of being implemented and/or performing any of the functionality set forth hereinabove.

[0065] In computing node 10 there is a computer system/server 12, which is operational with numerous other general purpose or special purpose computing system

environments or configurations. Examples of well-known computing systems,

environments, and/or configurations that may be suitable for use with computer system/server 12 include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, and distributed cloud computing environments that include any of the above systems or devices, and the like.

[0066] Computer system/server 12 may be described in the general context of computer system-executable instructions, such as program modules, being executed by a computer system. Generally, program modules may include routines, programs, objects, components, logic, data structures, and so on that perform particular tasks or implement particular abstract data types. Computer system/server 12 may be practiced in distributed cloud computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed cloud computing environment, program modules may be located in both local and remote computer system storage media including memory storage devices.

[0067] As shown in Fig. 8, computer system/server 12 in computing node 10 is shown in the form of a general-purpose computing device. The components of computer system/server 12 may include, but are not limited to, one or more processors or processing units 16, a system memory 28, and a bus 18 that couples various system components including system memory 28 to processor 16. [0068] Bus 18 represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, Peripheral Component Interconnect (PCI) bus, Peripheral Component Interconnect Express (PCIe), and Advanced Microcontroller Bus Architecture (AMBA).

[0069] Computer system/server 12 typically includes a variety of computer system readable media. Such media may be any available media that is accessible by computer system/server 12, and it includes both volatile and non-volatile media, removable and non-removable media.

[0070] System memory 28 can include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and/or cache memory 32. Computer system/server 12 may further include other removable/non-removable, volatile/non-volatile computer system storage media. By way of example only, storage system 34 can be provided for reading from and writing to a non-removable, non-volatile magnetic media (not shown and typically called a "hard drive"). Although not shown, a magnetic disk drive for reading from and writing to a removable, non-volatile magnetic disk (e.g., a "floppy disk"), and an optical disk drive for reading from or writing to a removable, non-volatile optical disk such as a CD-ROM, DVD-ROM or other optical media can be provided. In such instances, each can be connected to bus 18 by one or more data media interfaces. As will be further depicted and described below, memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of embodiments of the disclosure.

[0071 ] Program/utility 40, having a set (at least one) of program modules 42, may be stored in memory 28 by way of example, and not limitation, as well as an operating system, one or more application programs, other program modules, and program data. Each of the operating system, one or more application programs, other program modules, and program data or some combination thereof, may include an implementation of a networking environment. Program modules 42 generally carry out the functions and/or methodologies of embodiments as described herein.

[0072] Computer system/server 12 may also communicate with one or more external devices 14 such as a keyboard, a pointing device, a display 24, etc.; one or more devices that enable a user to interact with computer system/server 12; and/or any devices (e.g., network card, modem, etc.) that enable computer system/server 12 to communicate with one or more other computing devices. Such communication can occur via Input/Output (I/O) interfaces 22. Still yet, computer system/server 12 can communicate with one or more networks such as a local area network (LAN), a general wide area network (WAN), and/or a public network (e.g., the Internet) via network adapter 20. As depicted, network adapter 20

communicates with the other components of computer system/server 12 via bus 18. It should be understood that although not shown, other hardware and/or software

components could be used in conjunction with computer system/server 12. Examples, include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data archival storage systems, etc.

[0073] The present disclosure may be embodied as a system, a method, and/or a

computer program product. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present disclosure.

[0074] The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non- exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory

(EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire. [0075] Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program

instructions for storage in a computer readable storage medium within the respective computing/processing device.

[0076] Computer readable program instructions for carrying out operations of the present disclosure may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++ or the like, and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The computer readable program instructions may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present disclosure.

[0077] Aspects of the present disclosure are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the disclosure. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions. [0078] These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a

programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks.

[0079] The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the

functions/acts specified in the flowchart and/or block diagram block or blocks.

[0080] The flowchart and block diagrams in the Figures illustrate the architecture,

functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the

flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.

[0081 ] The descriptions of the various embodiments of the present disclosure have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

CLAIMS What is claimed is:

1. A system comprising:

a computing node comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor of the computing node to cause the processor to perform a method comprising:

receiving attributes of a future inspection of a factory;

receiving historical data related to the future inspection;

extracting a plurality of features from the attributes of the future inspection and

the historical data;

providing the plurality of features to a trained classifier;

obtaining from the trained classifier a risk score indicative of a probability of failure of the future inspection.

2. The system of Claim 1 , the method further comprising pre-processing the historical data.

3. The system of Claim 2, wherein pre-processing the data comprises

aggregating the historical data.

4. The system of Claim 3, wherein pre-processing the data further comprises filtering the data.

5. The system of Claim 1 , wherein the data further comprise performance history of the factory.

6. The system of Claim 1 , wherein the data further comprise geographic information of the factory.

7. The system of Claim 1 , wherein the data further comprise ground truth risk scores.

8. The system of Claim 1 , wherein the data further comprise product data of the

factory.

9. The system of Claim 1 , wherein the historical data span a predetermined time

window.

10. The system of Claim 1 , wherein

providing the plurality of features to the trained classifier comprises sending the plurality of features to a remote risk prediction server, and

11. The system of Claim 1 , wherein extracting the plurality of features comprises removing features with a low correlation to a target variable.

12. The system of Claim 1 , wherein extracting the plurality of features comprises

applying a dimensionality reduction algorithm.

13. The system of Claim 1 , wherein extracting the plurality of features from the

historical data comprises applying an artificial neural network.

14. The system of Claim 13, wherein applying the artificial neural network

comprises receiving a first feature vector as input, and outputting a second feature vector, the second feature vector of a smaller dimensionality than the first feature vector.

15. The system of Claim 1 , the method further comprising:

providing the risk score to a user.

16. The system of Claim 15, wherein providing the risk score to the user comprises

sending the risk score to a mobile or web application.

17. The system of Claim 16, wherein said sending is performed via a wide area

network.

18. The system of Claim 1 , wherein the trained classifier comprises an artificial

neural network.

19. The system of Claim 1 , wherein the trained classifier comprises a support

vector machine.

20. The system of Claim 1 , wherein obtaining the risk score comprises applying a gradient boosting algorithm.

21. The system of Claim 1 , wherein the risk score is related to the probability by a linear mapping.

22. The system of Claim 1 , wherein the method further comprises:

measuring performance of the trained classifier by comparing the risk score to a

ground truth risk score;

optimizing parameters of the trained classifier according to the performance.

23. The system of Claim 22, wherein optimizing the parameters of the trained

classifier comprises modifying hyperparameters of a trained machine learning model.

24. The system of Claim 23, wherein optimizing the parameters of the trained

classifier comprises replacing a first machine learning algorithm with a second machine learning algorithm, the second machine learning algorithm comprising hyperparameters configured to improve the performance of the trained classifier.

25. A method comprising:

receiving attributes of a future inspection of a factory;

receiving historical data related to the future inspection;

extracting a plurality of features from the attributes of the future inspection and the

historical data;

providing the plurality of features to a trained classifier;

26. The method of Claim 25, further comprising pre-processing the historical data.

27. The method of Claim 26, wherein pre-processing the data comprises

aggregating the historical data.

28. The method of Claim 27, wherein pre-processing the data further comprises filtering the data.

29. The method of Claim 25, wherein the data further comprise performance history of the factory.

30. The method of Claim 25, wherein the data further comprise geographic information of the factory.

31. The method of Claim 25, wherein the data further comprise ground truth risk scores.

32. The method of Claim 25, wherein the data further comprise product data of the factory.

33. The method of Claim 25, wherein the historical data span a predetermined time window.

34. The method of Claim 25, wherein

35. The method of Claim 25, wherein extracting the plurality of features comprises removing features with a low correlation to a target variable.

36. The method of Claim 25, wherein extracting the plurality of features comprises applying a dimensionality reduction algorithm.

37. The method of Claim 25, wherein extracting the plurality of features from the historical data comprises applying an artificial neural network.

38. The method of Claim 37, wherein applying the artificial neural network

39. The method of Claim 25, further comprising:

providing the risk score to a user.

40. The method of Claim 39, wherein providing the risk score to the user comprises

sending the risk score to a mobile or web application.

41. The method of Claim 40, wherein said sending is performed via a wide area

network.

42. The method of Claim 25, wherein the trained classifier comprises an artificial

neural network.

43. The method of Claim 25, wherein the trained classifier comprises a support

vector machine.

44. The method of Claim 25, wherein obtaining the risk score comprises applying a

gradient boosting algorithm.

45. The method of Claim 25, wherein the risk score is related to the probability by a

linear mmapping.

46. The method of Claim 25, further comprising:

ground truth risk score;

optimizing parameters of the trained classifier according to the performance.

47. The method of Claim 46, wherein optimizing the parameters of the trained

48. The method of Claim 47, wherein optimizing the parameters of the trained

49. A computer program product for inspection risk estimation, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause the processor to perform a method comprising:

receiving attributes of a future inspection of a factory;

receiving historical data related to the future inspection;

extracting a plurality of features from the attributes of the future inspection and the historical data;

providing the plurality of features to a trained classifier;

50. The computer program product of Claim 49, the method further comprising preprocessing the historical data.

51. The computer program product of Claim 50, wherein pre-processing the data comprises aggregating the historical data.

52. The computer program product of Claim 51 , wherein pre-processing the data further comprises filtering the data.

53. The computer program product of Claim 49, wherein the data further

comprise performance history of the factory.

54. The computer program product of Claim 49, wherein the data further

comprise geographic information of the factory.

55. The computer program product of Claim 49, wherein the data further comprise ground truth risk scores.

56. The computer program product of Claim 49, wherein the data further comprise product data of the factory.

57. The computer program product of Claim 49, wherein the historical data

span a predetermined time window.

58. The computer program product of Claim 49, wherein

59. The computer program product of Claim 49, wherein extracting the plurality of features comprises removing features with a low correlation to a target variable.

60. The computer program product of Claim 49, wherein extracting the plurality of features comprises applying a dimensionality reduction algorithm.

61. The computer program product of Claim 49, wherein extracting the plurality of features from the historical data comprises applying an artificial neural network.

62. The computer program product of Claim 61 , wherein applying the artificial neural network comprises receiving a first feature vector as input, and outputting a second feature vector, the second feature vector of a smaller dimensionality than the first feature vector.

63. The computer program product of Claim 49, the method further

comprising: providing the risk score to a user.

64. The computer program product of Claim 63, wherein providing the risk score to the user comprises sending the risk score to a mobile or web application.

65. The computer program product of Claim 64, wherein said sending is performed via a wide area network.

66. The computer program product of Claim 49, wherein the trained classifier comprises an artificial neural network.

67. The computer program product of Claim 49, wherein the trained classifier

comprises a support vector machine.

68. The computer program product of Claim 49, wherein obtaining the risk score comprises applying a gradient boosting algorithm.

69. The computer program product of Claim 49, wherein the risk score is related to the probability by a linear mapping.

70. The computer program product of Claim 49, wherein the method further comprises:

measuring performance of the trained classifier by comparing the risk score to a ground truth risk score;

optimizing parameters of the trained classifier according to the performance.

71. The computer program product of Claim 70, wherein optimizing the parameters of the trained classifier comprises modifying hyperparameters of a trained machine learning model.

72. The computer program product of Claim 71 , wherein optimizing the parameters of the trained classifier comprises replacing a first machine learning algorithm with a second machine learning algorithm, the second machine learning algorithm comprising hyperparameters configured to improve the performance of the trained classifier.