WO2023279174A1

WO2023279174A1 - Project schedule analysis tool

Info

Publication number: WO2023279174A1
Application number: PCT/AU2022/050725
Authority: WO
Inventors: John Lewis
Original assignee: Lewis Woolcott Pty Ltd
Priority date: 2021-07-09
Filing date: 2022-07-11
Publication date: 2023-01-12

Abstract

A project analysis tool is provided that is able to provide an objective critical path across a plurality of activities in one or more project files, avoiding outcomes based upon subjectivity, emotion, and bias. The project analysis tool is configured to: receive one or more project schedule files, each including a plurality of activities, a timing relating to each of the activities, each of the project schedule files relating to a version of a project schedule relating to a project; receive an end activity of the plurality of activities; and generate a critical path between the plurality of activities, by iteratively tracing back from the end activity by selecting the most probable driving predecessor of the activities in the one or more project files according to a plurality of attributes and associated weightings.

Description

PROJECT SCHEDULE ANALYSIS TOOL

TECHNICAL FIELD

[0001] The present invention relates to project schedules. In particular, although not exclusively, the present invention relates to analysis tools for analysing delays in project schedules.

BACKGROUND ART

[0002] In large projects, planning is generally centred around a project schedule, which identifies a plurality of activities to be performed with reference to a timeline, and dependencies between the activities. As such, the project schedule defines a sequencing of activities needed to be performed to fulfil the project scope.

[0003] As activities may be dependent on other activities, a delay in performing one activity may impact other activities, and potentially delay completion of the project. In many cases, the activities are performed by different contractors, and contractual arrangements are put in place to ensure the timely completion of each of the activities.

[0004] Even so, activities may be delayed, causing delay and/or disruption to the project. This may result in delay claims being made. One problem, however, with claims relating to delay, is that the complex relationship between different activities and their timings may make it difficult to identify the delay or impact of a delay in one activity on the project as a whole. In other words, quantifying delay claims can be complex.

[0005] In many cases, experts are used to identify the schedule critical path, which is the longest (in time) path of connected activities in the schedule, as it defines the minimum time required to complete the project, according to the schedule. Establishing whether a delay impacts the critical path has a large weighting on the outcome of any dispute as to damage or cost follow-on from the event.

[0006] One problem with such approach is that establishing the critical path after the event has no well-defined solution, and is generally complex, laborious and mostly performed manually. This results in manual analysis influenced by subjectivity, emotion, and bias, and is more likely to result in disagreement between parties.

[0007] As such, there is clearly a need for an improved project analysis tool to help perform forensic investigations of work disputes related to project delivery not adhering to schedule. [0008] It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

SUMMARY OF INVENTION

[0009] The present invention relates to project analysis tools and methods, which may at least partially overcome at least one of the abovementioned disadvantages or provide the consumer with a useful or commercial choice.

[0010] With the foregoing in view, the present invention in one form, resides broadly in a project analysis tool configured to: receive one or more project schedule files, each including a plurality of activities, a timing relating to each of the activities, each of the project schedule files relating to a version of a project schedule and a project; receive or determine an end activity of the plurality of activities; and determine a critical path between the plurality of activities, by iteratively tracing back from the end activity by selecting the most probable driving predecessor of the activities in the one or more project files according to a plurality of attributes and associated weightings.

[0011] Advantageously, by iteratively tracing back from the end activity by selecting the most probable driving predecessor in the project files, the tool is able to provide an objective critical path, avoiding outcomes based upon subjectivity, emotion, and bias, and instead provide a transparent and calculated analysis.

[0012] Preferably, the one or more project schedule files comprise a plurality of project schedule files. The project schedule files may relate to updates of a project over time.

[0013] Preferably, the one or more project schedule files includes one or more dependencies between two or more of the activities thereof.

[0014] The critical path may include activities from multiple project schedule files.

[0015] The project files may be compiled from the output of schedule software of various, different vendors.

[0016] Preferably, the plurality of project schedule files are associated with a status date, wherein the most probable driving predecessor is selected in part according to the status date.

[0017] The tool may be configured to generate a score for each preceding activity at least in part according to the plurality of attributes and associated weightings, wherein the most probable driving predecessor is selected according to the score.

[0018] Preferably, the weightings are defined independently of the schedule files.

[0019] Preferably, the attributes relate to attributes of or associated with the schedule files.

[0020] The weightings may be revised and amended by a user.

[0021] Preferably, the weightings are hierarchically defined. In particular, the weightings may include sub-weightings.

[0022] Preferably, the tool is configured to generate a log file including the score associated with each of the preceding activities.

[0023] Preferably, the tool includes a graphical user interface (GUI).

[0024] The GUI may be configured to display one or more activities with reference to a Gantt chart.

[0025] The GUI may be configured to display one or more of the schedule files. The GUI may be configured to enable a user to select the end activity of the plurality of activities.

[0026] The GUI may be configured to display the critical path. The critical path may be displayed at least in part using a Gantt chart.

[0027] Preferably, the critical path is displayed such that each of the activities includes an indicator, indicating from which schedule file the activity relates.

[0028] The GUI may be configured to display candidate predecessors for a selected activity. The candidate predecessors may be displayed with reference to a score.

[0029] The GUI may be configured to enable a user to select an alternate predecessor for a selected activity. The tool may then iteratively trace back from the selected alternate predecessor by selecting the most probable driving predecessor in the plurality of project files according to a plurality of attributes and associated weightings.

[0030] The plurality of project schedule files may include a baseline schedule file, and a plurality of subsequent schedule files relating to each schedule update during the course of the project, wherein the GUI is configured to display activities with reference to activities of the baseline schedule file. [0031] Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention.

[0032] The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.

BRIEF DESCRIPTION OF DRAWINGS

[0033] Various embodiments of the invention will be described with reference to the following drawings, in which:

[0034] Figure 1 illustrates a simplified schematic of a project schedule analysis tool, according to an embodiment of the present invention.

[0035] Figure 2 illustrates a screenshot of an example of a Gantt chart screen of the tool of Figure 1 , according to an embodiment of the present invention.

[0036] Figure 3 illustrates a method of determining a critical path of a project from a plurality of project schedule files, according to an embodiment of the present invention.

[0037] Figure 4 illustrates a screenshot of a critical path screen of the tool of Figure 1 , according to an embodiment of the present invention.

[0038] Figure 5 illustrates a screenshot of a weighting screen of the tool of Figure 1 , according to an embodiment of the present invention.

[0039] Figure 6 illustrates a screenshot of a sub-weighting screen of the tool of Figure 1 , according to an embodiment of the present invention.

[0040] Figure 7 illustrates a screenshot of a profile summary screen of the tool of Figure 1 , according to an embodiment of the present invention.

[0041] Figure 8 illustrates a screenshot of an activity profile screen of the tool of Figure 1 , according to an embodiment of the present invention.

[0042] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. DESCRIPTION OF EMBODIMENTS

[0043] Figure 1 illustrates a simplified schematic of a project schedule analysis tool 100, according to an embodiment of the present invention. The project schedule analysis tool 100 receives a plurality of project schedule files 105, relating to a project after project execution and defining changes in the project over time, stores these in a memory 110, and analyses these files using a processor 115, to find the most logical critical path for the project. This may then be used after completion of the project to help perform forensic investigations of work disputes related to the project not adhering to schedule, or during a project, e.g. as part of monthly reviews.

[0044] Initially, the plurality of schedule files 105 are provided to the project schedule analysis tool 100, using a user interface 120, such as a graphical user interface of a website or software application. The schedule files 105 each comprise a plurality of activities to be performed, timing information relating to each of the activities, and dependencies between the activities.

[0045] The schedule files 105 may be provided in any one (or more) of a variety of formats, typically as they were used in project management or a variant thereof, and thus will also include a variety of other attributes relating to the activities. The XER file format, by Oracle Corporation of Texas, United States, is believed to be particularly beneficial for this purpose, as it provides an efficient means to export and communicate the project schedule information.

[0046] The schedule files 105 include a baseline schedule file, and a plurality of schedule files relating to each schedule update during the course of the project. The schedule files 105 are each associated with a schedule status date, which relates to the date at which that version of the schedule relates. In short, during the project, the schedule will be updated as the project schedule changes, and new schedule files are created.

[0047] Once the schedule files 105 have been uploaded, the tool 100 displays the schedule data associated with the latest status data, or a schedule selected by the user, as a Gantt chart on the user interface 120.

[0048] Figure 2 illustrates a screenshot 200 of an example of a Gantt chart screen of the tool 100, according to an embodiment of the present invention.

[0049] The Gantt chart includes a plurality of activity elements 205, arranged in rows. Each activity element 205 optionally comprises an activity code 205a, an activity name 205b, a start date 205c and a finish date 205d. A plurality of other activity attributes, which may be selectable by the user, may optionally be shown in the row. The skilled addressee will, however, readily appreciated that many columns (fields) would generally be present. A chart element 210 is also provided wherein each row is illustrated with reference to a bar 210a and a timeline, such that the width and location of the bars 210a define the time and duration of the associated activity.

[0050] The Gantt chart screen may display the schedule with reference to any status date selectable by the user, and displays the schedule with reference to the baseline (if identified) and the longest path after traceback (if executed). In Figure 2, the schedule is displayed as the earliest schedule (corresponding to the baseline), but in many circumstances, the latest schedule would be displayed by default. In other words, the schedule (white) and baseline (diagonal stripes) are fully overlapping in Figure 2, but would generally not be fully overlapping in case another schedule were displayed.

[0051] Each of the bars 210a of the Gantt chart screen is selectable, enabling a user to see details of the associated activity. These details can include project schedule properties, such as priority, dependency, constraints, project dates, and the like, as will be readily understood by the skilled addressee.

[0052] The Gantt chart screen also includes a wide range of display parameters and configurations, including the ability to filter activities, and display charts at varying Work Breakdown Structure (WBS) level. This is particularly useful in assisting the user in understanding the project schedule on a variety of levels.

[0053] The Gantt chart screen also provides for conditional formatting, to enable the user to highlight cells based on the value of the cell, using several common logical rules. This is particularly useful in initial analysis, when the user is attempting to get an overview over key points in the timeline.

[0054] In order to use the tool 100 to identify a critical path between activities from the plurality of project schedule files 105, the user first selects a bar 210a corresponding to an end point in the schedule, and then activates the traceback operation using a button or other interface device. The end point in the schedule is the last of the “critical” activities in the project, but need not be the last activity in the project. As an illustrative example, a project may include rehabilitation activities that occur in parallel to critical activities, potentially extending well after all of the critical activities are completed.

[0055] The tool 100 then uses a plurality of attributes and their associated weightings 125, to calculate the most probable critical path back through the different schedule files 105, over time. This is achieved sequentially by determining a driving predecessor in the schedules, iteratively back to the start of the project.

[0056] Figure 3 illustrates a method 300 of determining a critical path of a project from a plurality of project schedule files, according to an embodiment of the present invention. The method 300 may be similar or identical to the method performed by the tool 100, and as such, the plurality of project schedule files include files relating to changes in the project over time.

[0057] Initially, at step 305, an activity of the plurality of activities is received as the initial selected activity. This initial selected activity comprises the last (it time) critical activity to which the method is performed. As such, it is typically the last critical activity in the project, as defined by a user of the tool 100. The most logical end activity will usually be something like “practical completion”, “finish milestone", “first power” etc.

[0058] At step 310, the preceding activities of the selected activity are analysed to determine their likelihood as a predecessor in the critical path. This may correspond to a completeness of the coding between an activity and the predecessor.

[0059] In this regard, a plurality of schedule attributes of each of the preceding activities are analysed with reference to the selected activity and an associated weighting. The attributes include measures, for each activity in the schedule, of the resourcing assigned, the time and calendar assigned and time taken, any constraints applied to the activity, including required and implied sequencing in relation to other activities, the costs associated with the activity and the positioning and naming of the activity in relation to all other activities within the schedule.

[0060] Each attribute has a weighting associated with it, to ensure that each attribute is given appropriate weighting, and the resulting decision is sensible with a high possibility of being correct.

[0061] The weightings are divided into defined links, implied links, path values and similarities values.

[0062] The defined links are actual schedule relationships, coded into the schedule.

[0063] The implied links are links implied, but not coded into the schedule, such as where the finish of an activity closely relates to the start of another activity.

[0064] The path value is a summary score of the path attributes, which measure the ‘value’ of the path leading to the candidate.

[0065] Finally, the similarity value is a summary score of the similarity of the candidate activity to the current activity, and is based on factors such as project, file, WBS and the like.

[0066] In some embodiments, the attributes may be associated with Activity Name, Available Float, Linkage, Duration, WBS relevance, Resourcing, and User Coding.

[0067] The weightings include default values, but may be changed by the user as outlined below.

[0068] When analysing the preceding activities, the analysis is performed using the plurality of project schedule files. In this regard, the status dates of the project files are used during the traceback analysis to order the schedules. The traceback analysis begins with activities in the schedule with the latest status date, and as the traceback progresses, activities from earlier status dates are also considered.

[0069] The method may automatically and dynamically adjust weightings based on the actual schedule content. In this sense, the method may automatically focus on attributes that have the greatest impact, ignoring attributes that are static or near static.

[0070] Finally, as outlined below, the weighting can be tuned by the user to follow their preference more closely for weightings.

[0071] The output of the analysis is a score for each candidate predecessor according to the attributes and the weightings, the score indicative of a likelihood of the candidate predecessor being the driving predecessor.

[0072] At step 315, a preceding activity is selected based upon the analysis. This may be performed by ranking the preceding activities based upon the score from the analysis, and selecting the highest scoring candidate activity.

[0073] At step 320, the selected preceding activity is added to the list of critical activities. The list of critical activities ultimately becomes the identified critical path for the project, and is thus continuously added to until the path is defined.

[0074] Steps 310-320 are repeated with the selected preceding activity. This process is then repeated until the start of the project is reached.

[0075] Finally, at step 325, the list of critical activities is output. The list of critical activities may be exported and may be displayed as a Gantt chart.

[0076] During the method 300 and operation of the tool 100, a log of each decision made in determining the critical activities (tracing the path), and the associated ranking is made. The log may then be used to support and document the choice of path.

[0077] Figure 4 illustrates a screenshot 400 of a critical path screen of the tool 100, according to an embodiment of the present invention. In this case, the critical path has been traced backwards from activity 135 “Site Clean Ups & Demob” in one schedule file, to activity 4 “Tender Re-view Period” in an earlier schedule file.

[0078] The critical path screen is similar to the Gantt chart screen of Figure 2 and includes a plurality of critical activity elements 405, arranged in rows. Each critical activity element 405 comprises an activity code 405a, an activity name 405b, a start date 405c and a finish date 405d, much like the activity element 205. These activity attributes, and a plurality of other activity attributes may optionally be selected by the user for display on the row. A chart element 410 is also provided wherein each row is illustrated with reference to a bar 410a and a timeline, such that the width and location of the bars 210a define the time and duration of the associated activity.

[0079] The Gantt chart screen displays the critical schedule, which comprises critical activity elements 405 from the plurality of project schedule files. A project file icon 415 indicates, using colour coding (shown with shading in Figure 4), which schedule from the plurality of project schedule files the critical activity element 405 is taken. This enables the user to quickly see changes in the project files used, with reference to the timeline and Gantt chart.

[0080] Each of the bars 410a of the Gantt chart screen is selectable, enabling a user to see details of the scoring of all candidate activities, that is, all activities that were considered as the possible best predecessor to the selected critical activity element 405.

[0081] The data behind the scoring for the candidate activities is also viewable, which allows the user to review why a score has been assigned, by reviewing the actual schedule data that has been compared to derive the score.

[0082] When selecting a critical activity element, all possible predecessors, or a subset of the highest ranked of these, are shown in colour coded (or shaded) format, with their associated score. This enables the user to review the critical path elements, and override them if desired. This can often occur where the user, as an expert, has other compelling knowledge as to which activities lie on the real critical path.

[0083] In particular, the tool 100 enables the user to select a critical activity element 405, and change the predecessor. In such case, the algorithm then works back from the new (selected) predecessor to the beginning of the project. The user may perform such changes multiple times until he or she is happy with the result.

[0084] When changing a predecessor, the user is prompted to enter a brief description as to why the chosen activity was chosen, which is then stored in the audit log.

[0085] As outlined above, the weights used in the scoring may be changed according to the preference of a user.

[0086] Figure 5 illustrates a screenshot 500 of a weighting screen of the tool 100, according to an embodiment of the present invention. The weighting illustrated in Figure 5 is the default weighting used by the tool 100, but may be changed.

[0087] The weighting screen includes a plurality of weighting elements 505, each including a weight input field 510. The user may manually enter in a desired weighting for the weighting elements into the weight input field 510.

[0088] The sum of the weightings in the weighting screen is constrained to be 100, so changing the weighting for one weighting element 505 will result in the other weightings changing. Each weighting element 505 includes, however, a lock radio button 515, enabling the weighting for that element to be locked (i.e. prevent it from adjusting automatically).

[0089] Finally, the weighting elements 505 are each associated with a plurality of sub elements, and a detail button 520 enables the user to see the sub-elements and their associated weights, and update these.

[0090] Figure 6 illustrates a screenshot of a sub-weighting screen of the tool 100, according to an embodiment of the present invention. The sub-weighting screen is similar to the weighting screen of Figure 5, but includes sub-elements, in this case, similarity sub-elements.

[0091] In particular, the sub-weighting screen includes a plurality of sub-weighting elements 605, similar to the weighting element 505.

[0092] The sum of the total is constrained to be 100, and individual weightings can be locked if required, as outlined in the weighting screen.

[0093] Although the sum is set to 100, the actual weighting used on any of these attributes is factored by the summary weighting in the weighting screen. For example, the author weighting has a value of 6.0. But if the weighting for the total similarity score is 50.0, then the overall weighting for author will be 3.0 (6 times 50 divided by 100).

[0094] While only a single critical path has been illustrated, in some embodiments multiple critical paths may be evaluated. In such case, an overall score is calculated for each critical path according to a sum of the scores associated with the path. Each critical path may then be ranked according to the overall score, and a final critical path may be selected based upon the ranking.

[0095] Such overall score may also be indicative of a “health” of the critical path, which may be presented to the user. The overall score, or a distribution of overall scores, may be presented to the user an indicator of a level of uncertainty in the critical path.

[0096] The tool 100 also enables users to analyse the schedules, and in particular changes in activities across the schedule.

[0097] Figure 7 illustrates a screenshot 700 of a profile summary screen of the tool 100, according to an embodiment of the present invention.

[0098] The profile summary screen includes a plurality of attribute elements 705, arranged as rows, and shows how many activities have changed between each of the schedules, arranged as columns and ordered by status date. Each attribute element 705 and schedule combination is represented by a cell, which includes an indicator of how many activities have changed, and is colour coded (in Figure 7 shaded), such that large changes are shaded red (dark shading in Figure 7 to represent red), and no changes are shaded green (white in Figure 7 to represent green).

[0099] The profile summary screen can be useful when forming an overall view of when the schedule has changed during project progress, particularly when the schedule structure has changed.

[00100] Figure 8 illustrates a screenshot of an activity profile screen of the tool 100, according to an embodiment of the present invention.

[00101] The activity profile screen includes a plurality of activity elements 805, arranged as rows, and shows how many attributes have changed between each of the schedules, arranged as columns and ordered by status date. Each activity element 805 and schedule combination is represented by a cell, which includes an indicator of how many attributes have changed, and is colour coded (in Figure 8 shaded), such that large changes are shaded red (dark shading in Figure 8 to represent red), and no changes are shaded green (white in Figure 8 to represent green).

[00102] The activity profiles are useful to view exactly what changes have been made to activity attributes over the course of the project progress. While some attributes (such as Finish) are expected to change more frequently, others would normally be expected to remain static and are of interest when changed (such as constraints).

[00103] In addition to determining a critical path, the tools described above may be used for project schedule analytics.

[00104] In particular, the tools may provide the ability to directly view and compare a user selected number of generated critical paths to evaluate periods of consistently strong coding versus periods of consistently weak coding which could be useful for determining where schedule execution may have been at its most volatile. Such configuration may also be useful for determining periods of the project where junctions between critical paths occur, i.e. sections where an activity has many strong predecessor activities to branch down.

[00105] Similarly, the tools may include the ability to determine where activities frequently occur on critical path scenarios to aid in assessing the overall strength of a selected critical path activity.

[00106] The tools may visually identify the weakest section of a critical path, e,g, through colour coding, shading, or otherwise. By highlighting these sections, the user is able to identify potential vulnerabilities in the critical path.

[00107] Finally, the analysis may include an analysis of the scheduler program coding, identifying consistent areas of coding weakness e.g. poor linkage overall, coding activities that are too long for the project, missing resourcing, etc.

[00108] While the above examples illustrate a number of attributes used in the decision, the skilled addressee will readily appreciate that several more attributes are likely used. The inventor(s) believe that the following activity attributes are particularly relevant: Links (relationships), including defined (extant) and implied; Path values, including predecessors on path, total, maximum and weighted average, work on path, total, maximum and weighted average, durations on path, total, maximum and weighted average, and float on path, total, minimum and weighted average; and similarity values, including project, file (schedule file), WBS and activity name, planner (author and last editor), primary resource, resourcing (by name and rate), and date of creation and sequence ID.

[00109] While the above examples describe a single project schedule file defining the project for each status (time) period, the skilled addressee will readily appreciate that multiple files may be used to define the project at different points of time. As an illustrative example, principal contractors may need to incorporate multiple sub-contract schedules relating to different points in time and/or different aspects of the project. Similarly, different project schedule files may define the project at different levels, rather than in a single large project schedule file. In many cases, these different project schedule files may relate to a different area or aspect of the project, and are often not linked by explicit dependencies. In such case, the schedule files, which may be in different formats, are loaded as a single project, and schedule files may be linked by iteratively tracing back through the activities in project files, as outlined above.

[00110] Additionally, while the above examples describe a plurality of project schedule files, the skilled addressee will readily appreciate that the methods and systems may be used to trace back in a single project schedule file to determine a critical path in that file.

[00111] Advantageously, the methods and tools described above enable a user, such as a forensic expert or planner, to iteratively trace back from any chosen end point with detailed guidance on which activities are the most probable driving predecessor. The process can run fully automated with detailed documentation of each decision taken.

[00112] As such, the methods and tools avoid outcomes based upon subjectivity, emotion, and bias, and instead provide a transparent and calculated analysis.

[00113] This may reduce claim time frames, and includes automated documentation of evidence of longest path, which reduces the likelihood of disputes, as the outcome is generated in a transparent manner.

[00114] In a live project environment, the methods and tools will allow a planner to easily identify critical path variance and delay when projects are updated. As an illustrative example, following a monthly update, it may not be clear which activities have potentially delayed the longest path, particularly across multiple schedule files, potentially in different file formats. By identifying the critical path in the overall project (and across all files), critical delays may be easily identified, which may assist in the timely submission and assessment of delay notices.

[00115] In the present specification and claims (if any), the word ‘comprising’ and its derivatives including ‘comprises’ and ‘comprise’ include each of the stated integers but does not exclude the inclusion of one or more further integers.

[00116] Reference throughout this specification to ‘one embodiment’ or ‘an embodiment’ means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases ‘in one embodiment’ or 'in an embodiment’ in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

[00117] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.

Claims

1 . A project analysis tool configured to: receive one or more project schedule files, each including a plurality of activities, a timing relating to each of the activities, each of the project schedule files relating to a version of a project schedule and a project; receive or determine an end activity of the plurality of activities; and determine a critical path between the plurality of activities, by iteratively tracing back from the end activity by selecting the most probable driving predecessor of the activities in the one or more project files according to a plurality of attributes and associated weightings.

2. The project analysis tool of claim 1 , wherein the one or more project schedule files comprises a plurality of project schedule files.

3. The project analysis tool of claim 2, wherein the plurality of project schedule files relate to updates of a project over time.

4. The project analysis tool of claim 2, wherein the critical path includes activities from multiple project schedule files.

5. The project analysis tool of claim 1 , wherein each project schedule file associated with a status date, wherein the most probable driving predecessor is selected in part according to the status date.

6. The project analysis tool of claim 1 , wherein the one or more project schedule files includes one or more dependencies between two or more of the activities thereof.

7. The project analysis tool of claim 1 , further configured to generate a score for each preceding activity at least in part according to the plurality of attributes and associated weightings, wherein the most probable driving predecessor is selected according to the score.

8. The project analysis tool of claim 1 , wherein the weightings are defined independently of the schedule files, and the attributes relate to attributes of or associated with the schedule files.

9. The project analysis tool of claim 1 , wherein the attributes relate to attributes of or associated with the schedule files.

10. The project analysis tool of claim 1 , wherein the weightings may be input, revised or amended by a user.

11. The project analysis tool of claim 1 , wherein the weightings are hierarchically defined, and the weightings include sub-weightings.

12. The project analysis tool of claim 1 , configured to generate a log file including the score associated with each of the preceding activities.

13. The project analysis tool of claim 1 , further including a graphical user interface (GUI), configured to display one or more activities with reference to a Gantt chart.

14. The project analysis tool of claim 1 , wherein the GUI is configurable to display one or more of the schedule files.

15. The project analysis tool of claim 1 , wherein the GUI is configurable to display the critical path.

16. The project analysis tool of claim 15, wherein the GUI is configured to display the critical path such that each of the activities includes an indicator, indicating from which schedule file the activity relates.

17. The project analysis tool of claim 1 , wherein the GUI is be configured to display candidate predecessors for a selected activity, wherein the candidate predecessors are displayed with reference to an associated score.

18. The project analysis tool of claim 17, wherein the GUI is configured to enable a user to select an alternate predecessor for a selected activity.

19. The project analysis tool of claim 18, wherein the iteratively traces back from the selected alternate predecessor by selecting the most probable driving predecessor in the plurality of project files according to a plurality of attributes and associated weightings.

20. The project analysis tool of claim 1 , wherein the plurality of project schedule files includes a baseline schedule file, and a plurality of subsequent schedule files relating to each schedule update during the course of the project, wherein the GUI is configured to display activities with reference to activities of the baseline schedule file.