JP2015072505A - Software verification device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To estimate influence of changing the design of an arbitrary processing block in a data flow diagram.SOLUTION: A software verification device decomposes processing to be executed by software into multiple pieces of processing, and generates a plurality of processing blocks indicating each processing and a data line showing processing flow of the processing block, to perform information processing. The software verification device includes: an influence database which stores processing to be executed by a processing block, and information indicating a degree of influence on information input to the processing block due to changing the processing executed by the processing block, in association with each other; and a calculation unit which refers to the influence database when processing executed by a first processing block out of a plurality of processing blocks is changed, and calculates a degree of influence on a second processing block, which is connected to the first processing block and located posterior to the first processing block, due to changing the processing to be executed by the first processing block.

Description

  The present invention relates to a software verification apparatus.

  A group of tools are used for software development.

  For example, the Computer Aided Software Environment (CASE) tool defines software development practices based on methodologies such as structured methods and object-oriented analysis in order to develop software. In addition, the CASE tool provides an editor for creating specifications using the document notation adopted by these methodologies. For example, those employing a structured method have an editor for drawing a diagram that graphically represents the data flow of an information system, such as a data flow diagram.

  For example, when the outline of the control system is expressed by a data flow diagram, the processing flow is expressed by “processing block” and “data line”. By using a data flow diagram, the overall picture of the system can be grasped, so that the efficiency of system design activities and reviews can be improved.

  There is known a software development support method for presenting information on related products according to the contents of correction when correcting an arbitrary product (for example, see Patent Document 1).

JP-A-9-16392

  In order to use the data flow diagram to find out the points of attention and points of interest in design activities and reviews, it often relies on the skills and intuition of designers and design reviewers.

  In particular, when a design change is made to a part of the control system, it is an extremely important process to estimate the range and the magnitude of the influence of the design change and to examine the response to the influence. Estimating the range and magnitude of the impact of design changes and examining the response to the impact is sometimes called DRBFM (Design Review based on Failure Modes).

  When performing DRBFM using a data flow diagram, a path obtained by mechanically tracing a data line from a location (processing block) where the design has been changed in order to express the influence of the design change can be set as the affected range. However, in this case, since the number of processing blocks that are affected by the number of processing blocks increases and increases in the subsequent stages, the affected range cannot be obtained efficiently. In other words, even such a very important process often relies on the skills and intuition of the designer and the person performing the design review.

  The present invention is to estimate the influence of a design change when a design change is made to an arbitrary processing block in the data flow diagram.

A software verification apparatus according to an embodiment of the disclosure includes:
A software verification device that decomposes a process executed by software into a plurality of processes, generates a plurality of processing blocks indicating each process, and a data line indicating a flow of processing by the processing block, and performs information processing,
When processing executed by a processing block is changed and processing executed by the processing block is changed, information indicating an influence degree indicating a degree of influence by the change of information input to the processing block is linked. Impact database,
When the processing executed by the first processing block among the plurality of processing blocks is changed, the influence processing database is referred to, connected to the first processing block, and the first processing block A second processing block that is a subsequent stage, and a calculation unit that calculates an influence degree due to a change in processing executed by the first processing block.

  According to the disclosed embodiment, when a design change is made to an arbitrary processing block in the data flow diagram, the influence of the design change can be estimated.

It is a figure which shows one Example of a software verification apparatus. It is a figure which shows an example of a data flow figure. It is a figure which shows one Example of operation | movement of a software verification apparatus. It is a figure which shows an example of a data flow figure. It is a figure which shows an example of an influence degree database.

Next, the form for implementing this invention is demonstrated, referring drawings based on the following Examples. Examples described below are merely examples, and embodiments to which the present invention is applied are not limited to the following examples.
In all the drawings for explaining the embodiments, the same reference numerals are used for those having the same function, and repeated explanation is omitted.

<Example>
<Software verification apparatus 100>
FIG. 1 shows an embodiment of the software verification apparatus 100. The software verification apparatus 100 verifies control software that controls an arbitrary system.

  When software to be verified, for example, control software (hereinafter referred to as “software”) is input, the software verification apparatus 100 automatically generates software verification requirements and verifies the software according to the verification requirements.

  Furthermore, when a part of software to be verified is changed due to a design change or the like, the software verification apparatus 100 calculates the influence of the part whose design is changed on the other part.

  The software verification apparatus 100 may be realized by a dedicated apparatus that mainly performs software verification, or may be realized by executing a control software verification application on a general-purpose computer. The software verification device 100 is configured by hardware such as a CPU, a storage device, and a display device.

  The verification target software may be written in a single language or may be written in a plurality of different languages. Various languages can be used as the description language. For example, it may be described in a procedural language such as C language or a data flow type modeling language such as Simulink.

  The software verification apparatus 100 includes a function model generation unit 102, an influence degree calculation part 104, an influence degree evaluation part 106, and an influence degree database 108. In FIG. 1, functional blocks for a portion for performing software verification are omitted.

  The function model generation unit 102 receives software to be verified. The function model generation unit 102 generates a function model from the verification target software. The function model covers the functions of the software by extracting and modeling points for software verification.

  The functional model is shown in a visible form so that a software verifier can easily read and understand the software functions. In this way, by clearly specifying it in the form of a functional model, it can be easily understood whether or not the software verification person covers the functions verified by looking at the functional model.

  Since the control function for realizing the software has various aspects, it is modeled with a function model corresponding to each aspect of the control function. For example, a control function for realizing software is modeled by a data flow graph model (DFG model) for a control flow, a state transition model for control mode switching, and a Timed Automata for timing problems.

  In one embodiment of the software verification apparatus 100, a data flow graph model is applied. It can be applied to models other than the data flow graph model. For example, when a state transition model is applied, the influence of the changed state on other states can be calculated. When expressing an outline of a control system by a data flow graph model, a control function executed by software is decomposed into one or a plurality of processes. A “processing block” is prepared to represent each processing, and the processing flow is represented by connecting the “processing blocks” with “data lines”.

  The “processing block” represents a process obtained by disassembling a control function executed by software. A “data line” represents a flow of information exchanged between processing blocks. The processing executed by the processing block at the preceding stage affects (gives) the processing at the processing block at the subsequent stage.

  FIG. 2 shows an example of a data flow diagram. The data flow diagram represents the control contents of the system.

  The data flow diagram shown in FIG. 2 includes a processing A block 202, a processing B block 204 connected to the processing A block 202 through a data line, and an output signal (information) from the processing A block 202 being input. This is represented by a process C block 206.

  Further, the data flow diagram is represented by a processing D block 208 that is connected to the processing B block 204 through a data line and receives an output signal (information) from the processing B block 204.

  Further, the data flow diagram is represented by a processing G block 214 which is connected to the processing D block 208 through a data line and receives an output signal (information) from the processing D block 208.

  Further, the data flow diagram is represented by a processing E block 210 and a processing F block 212 which are connected to the processing C block 206 through a data line, and which are subsequent stages to which an output signal (information) from the processing C block 206 is input.

  Further, the data flow diagram is represented by a process H block 216 which is connected to the process F block 212 by a data line and is a subsequent stage to which an output signal (information) from the process F block 212 is input.

  Returning to the description of the software verification apparatus 100.

  The influence calculation unit 104 is connected to the function model generation unit 102. An instruction for changing the processing executed by the processing block is input to the influence degree calculation unit 104. When a change occurs in a certain processing block due to a design change or the like, the influence degree calculation unit 104 calculates the influence degree given to the other processing blocks by the processing block in which the change has occurred. A database is prepared in which the calculation content and an influence coefficient representing the degree of influence on the information before the calculation are calculated by the calculation indicated by the calculation content, and is referred to when calculating the influence level.

  Based on the influence degree calculated by the influence degree calculation unit 104, the influence degree evaluation unit 106 evaluates the degree of influence given to other processing blocks by the processing block in which the change has occurred. For example, each processing block may be colored according to the degree of influence, or may be displayed in different colors. Further, a processing block having an influence degree equal to or greater than the threshold value and a processing block having an influence degree less than the threshold value may be displayed in different colors.

  The influence degree database 108 is connected to the influence degree calculation unit 104. The influence degree database 108 stores the calculation contents and an influence coefficient that represents the degree of influence on the information before the calculation by the calculation indicated by the calculation contents.

<Operation of Software Verification Device 100>
FIG. 3 shows the operation of the software verification apparatus 100.

  In step S302, the function model generation unit 102 generates a data flow diagram from the verification target software.

  In the example shown in FIG. 3, the software verification apparatus 100 generates a data flow graph including a sensor (1) 302, a processing A block 304-processing J block 322, and an actuator (1) 324-actuator (5) 332. To do. Process A-process J is executed by process A block 304-process J block 322, respectively.

  Sensor (1) 302 outputs detection values from various sensors. The process A block 304 to the process J block 322 perform various processes on the detection value from the sensor (1) 302. The actuator (1) 324-actuator (5) 332 converts information output from the processing A block 304 to the processing J block 322 into physical motion.

  In step S304, the influence degree calculation unit 104 calculates the influence degree that the process executed by the process block in which the change has occurred has on the process executed by another process block. For example, a case where a design change occurs in the process A executed by the process A block 304 will be described. When a design change occurs in the process A executed by the process A block 304, it is assumed that the process B block 306 and the process C block 308 connected to the process A block 304 and subsequent to the process A block 304 are affected. Is done. The influence degree calculation unit 104 calculates the influence degree due to the design change to the process A block 304 for the process B block 306 and the process C block 308. Here, as an example, a calculation example of the influence degree for the processing C block 308 will be described.

  As shown in FIG. 3, the processing C block 308 includes an adder (sum) 3082, an amplifier (gain) 3084, and a switch 3086. When calculating the degree of influence on the processing C block 308, the degree of influence calculating unit 104 acquires the degree of influence coefficient of the operator included in the processing C block 308 from the degree of influence database 108.

  In FIG. 3, as an example of the influence degree database 108, calculation contents by an operator applied to Simulink and an influence degree coefficient indicating the degree of influence exerted by the calculation represented by the calculation contents are linked. Here, the influence coefficient 0.8 of the adder (Sum) 3082, the influence coefficient 0.95 of the amplifier (Gain) 3084, and the influence coefficient 0.5 of the switch (Switch) 3086 are acquired. The influence degree calculation unit 104 calculates the influence degree of the processing C block 308 based on the influence degree coefficient acquired from the influence degree database 108.

  Here, since the signal output from the process A block 304 whose design is changed is directly input to the process C block 308, the influence degree is set to “1” (initial value). The adder 3082 adds the signal output from the processing A block 304 and the constant “5”. On the other hand, the influence coefficient of the adder 3082 is “0.8”. The influence degree calculation unit 104 calculates the influence degree of the output signal from the operator by multiplying the influence degree of the input signal to the operator and the influence degree coefficient of the operator. For example, the influence degree calculation unit 104 multiplies the influence degree 1 of the input signal to the adder 3082 by the influence coefficient 0.8 of the adder 3082, thereby reducing the influence degree 0 of the output signal from the adder 3082. .8 is calculated.

  The signal output from the adder 3082 is input to the amplifier 3084. The influence coefficient of the amplifier 3084 is 0.95. The influence degree calculation unit 104 multiplies the influence degree 0.8 of the input signal to the amplifier 3084 and the influence coefficient 0.95 of the amplifier 3084 to obtain the influence degree 0.76 of the output signal from the amplifier 3084. Calculate.

  The signal output from the amplifier 3084 is input to the switch 3086. The influence coefficient of the switch 3086 is 0.5. The influence calculation unit 104 multiplies the influence degree 0.76 of the input signal to the switch 3086 by the influence coefficient 0.5 of the switch 3086 to obtain the influence degree 0.38 of the output signal from the switch 3086. Calculate.

  The influence degree calculation unit 104 applies the above-described calculation to the process D block 310 connected to the process C block 308 and the process E block 312 with the influence degree of the input signal as 0.38. After the calculation for the processing D block 310, the processing D block 310 is connected to the processing D block 310, and the processing H block 318 and the processing I block 320, which are the subsequent stages, are described above with the influence degree of the input signal as the influence degree of the processing D block 310. Apply the operation. The calculation of the influence degree is preferably performed for each stage.

  In step S306, the influence degree evaluation unit 106 visualizes the calculation result of the influence degree for each processing block. For example, the influence degree evaluation unit 106 may represent the degree of influence by color shading. By expressing the degree of influence by the color shading, the user can intuitively determine the degree of influence. In the example illustrated in FIG. 3, coloring is performed on a processing block having an influence degree of 0.6 or more.

  According to an embodiment of the software verification apparatus, it is possible to estimate and visualize the influence of the processing by the processing block on the processing block of the subsequent stage with respect to an arbitrary processing block of the data flow diagram.

<Modification>
A software verification apparatus 100 shown in FIG. 1 can be applied as a modification of the software verification apparatus.

  One modification of the software verification apparatus is that the degree of influence associated with the processing executed by the processing block and the influence coefficient indicating the degree of influence on the information before the processing by the processing indicated by the processing content. A database is prepared. In the embodiment described above, the calculation content and the influence coefficient representing the degree of influence on the information before the calculation by the calculation indicated by the calculation content are stored in the influence database. On the other hand, in the modified example, the processing content and the influence coefficient indicating the degree of the influence on the information before the processing by the processing indicated by the processing content are stored in association with each other.

  When a process block is changed due to a design change or the like, the software verification device refers to the influence degree database when calculating the degree of influence of the process block on which the change has occurred on another process block.

  The function model generation unit 102 generates a data flow graph from the verification target software.

  FIG. 4 is a diagram illustrating an example of a data flow diagram.

  In the example illustrated in FIG. 4, the software verification apparatus 100 generates a data flow graph including the sensor (1) 402, the processing A block 404-the processing J block 422, and the actuator (1) 424 -actuator (5) 432. To do. Processing A-processing J is executed by processing A block 404-processing J block 422, respectively.

  The influence degree calculation unit 104 calculates the influence degree that the process executed by the process block in which the change has occurred on the process executed by another process block. For example, a case where a design change occurs in the process A executed by the process A block 404 will be described. When a design change occurs in the process A executed by the process A block 404, it is assumed that the process B block 406 and the process C block 408 connected to the process A block 404 and subsequent to the process A block 404 are affected. Is done. The influence degree calculation unit 104 calculates the influence degree due to the design change to the process A block 404 for the process B block 406 and the process C block 408. Here, as an example, a calculation example of the influence degree for the process B block 406 will be described.

As shown in FIG. 4, the processing content of the processing B block 406 is signal conversion.
When calculating the influence degree on the process B block 406, the influence degree calculation unit 104 acquires an influence degree coefficient associated with the process executed by the process B block 406 from the influence degree database 208.

  FIG. 5 shows an example of the impact database 208. In FIG. 5, the attribute of the process is associated with an influence coefficient indicating the degree of influence exerted by the process. Here, a signal conversion influence factor of 1.0 is acquired. The influence degree calculation unit 104 calculates the influence degree of the process B block 406 based on the influence degree coefficient acquired from the influence degree database 208.

  Here, since the signal output from the process A block 404 whose design is changed is directly input to the process B block 406, the influence degree is set to “1” (initial value). The influence degree calculation unit 104 calculates the influence degree of the output signal from the processing block by multiplying the influence degree of the input signal to the processing block by the influence degree coefficient of the processing block. For example, the influence degree calculation unit 104 multiplies the influence degree “1” of the input signal to the process B block 406 by the influence degree coefficient “1” of the process B block 406, thereby The influence level “1” of the output signal is calculated.

  The influence degree calculation unit 104 sets the influence degree of the input signal as the influence degree 1 of the output signal from the preceding process B block 406 for the process F block 414 and the process G block 416 connected to the process B block 406. Apply the operations described above. The calculation of the influence degree is preferably performed for each stage.

  The influence degree evaluation unit 106 visualizes the influence degree calculation result for each processing block. For example, the influence degree evaluation unit 106 may represent the degree of influence by color shading. By expressing the degree of influence by the color shading, the user can intuitively determine the degree of influence.

  According to a modification of the software verification apparatus, it is possible to estimate and visualize the influence of processing by a processing block on the processing block of the subsequent stage with respect to an arbitrary processing block of the data flow diagram.

  Since processing by the processing block and an influence coefficient indicating the degree of influence on the subsequent processing block by that processing are linked, the processing load is reduced compared to the case where the influence coefficient is linked to each calculation by the processing block it can.

  Although the present invention has been described above with reference to specific embodiments and modifications, each embodiment and modification is merely illustrative, and those skilled in the art will recognize various modifications, modifications, alternatives, and substitutions. You will understand examples. For convenience of explanation, an apparatus according to an embodiment of the present invention has been described using a functional block diagram, but such an apparatus may be implemented in hardware, software, or a combination thereof. The present invention is not limited to the above-described embodiments, and various variations, modifications, alternatives, substitutions, and the like are included without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 100 Software verification apparatus 102 Functional model production | generation part 104 Influence degree calculation part 106 Influence degree evaluation part 108 Influence degree database 208 Influence degree database

Claims (1)

A software verification device that decomposes a process executed by software into a plurality of processes, generates a plurality of processing blocks indicating each process, and a data line indicating a flow of processing by the processing block, and performs information processing,
When processing executed by a processing block is changed and processing executed by the processing block is changed, information indicating an influence degree indicating a degree of influence by the change of information input to the processing block is linked. Impact database,
When the processing executed by the first processing block among the plurality of processing blocks is changed, the influence processing database is referred to, connected to the first processing block, and the first processing block A software verification apparatus comprising: a calculation unit that calculates an influence degree due to a change in processing executed by the first processing block with respect to a second processing block that is a subsequent stage.

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