ISSN:1040-550X    

DOI:10.1002/smr.4360020102

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThis paper presents a model for understanding assembly programs for software maintenance. It is based on the theory that explicit representation of various structural and functional elements of code and multiple relationships among them will aid program understanding and thus software maintenance. We present a parsing technique to extract all the required elements from assembly code to populate the model. The model is a reverse engineering technique. We use the term reverse engineering in its broad sense to include specification as well as design recovery. Most features of this model have been implemented in a tool named “RETA” for Reverse Engineering Tool for Assembly programs.The model is useful for software maintenance activities such as program understanding, ripple effect analysis, and program re‐documentation. The ripple effect of a contemplated change is the parts of code that depend on the variable or a piece of code to be changed. Once the change is made, those parts need to be re‐examined for possible modification. The model generates a functional menu for a given application. The menu describes the functionality of each routine. It is a hierarchical presentation of major program routines, the sub‐routines supporting each major routine and so on. A routine at any level of detail consists of one or more paths through the code. Paths are presented as control flow sequences between code blocks. Code blocks, and hence functionalities, use and modify data.The maintainer locates the routine to be modified at the lowest level of detail within the functional menu. This automatically slices out the set of paths, and hence the set of code blocks, that have a role in the functionality to be changed. The code blocks in the slice determine the data that are used and modified within the routine to be changed. Path analysis and associated data‐used and data‐modified information are used to determine which code blocks are to be changed and which data roles are to be modified. The same set of relations are applied in reverse to identify the

ISSN:1040-550X    

DOI:10.1002/smr.4360020103

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractCOBOL‐implemented systems commonly rely on the PERFORM verb to provide structure and iteration in the software. Because of that key role, shortfalls in the use of PERFORM can lead to challenging difficulties in both enhancive and corrective maintenance. This paper explains the source of many of the symptoms by examining the way the compiler‐generated object code executes. Then it classifies the symptoms by their pattern and relates the classes to the normally hidden generated code. In closing, the paper offers six positive actions to improve COBOL software using the PERFORM verb, and points to their contribution in enhancive and corrective maintenance, software quality assurance, systems improvement, and the management of software maintena

ISSN:1040-550X    

DOI:10.1002/smr.4360020104

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractSoftware maintenance is necessitated to a large extent by changing user requirements. However, the relationship between the user requirements and the implemented software system is not made explicit in current development approaches, making the mapping of changing requirements to corresponding maintenance activities difficult. The teleological approach advocates the construction of a model which links the components of a software system to the concepts of the application domain which they implement, i.e to user requirements. Subsequently, the teleological model is used for simulating the actual maintenance activities, as they are triggered by the changing requirements, and for identifying their nature and estimating their cost.

ISSN:1040-550X    

DOI:10.1002/smr.4360020105

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe Jackson methodology for systems development is seen as a formal methodology. Although it is formal, the analyst has a freedom to specify models of problems in alternative ways without giving any indication which one is the better. Proposals to extend the methodology with the concepts ‘(near) static entity’ and ‘static roles’ give the analyst even more freedom than before. From the maintenance point of view this can lead to problems of understandability of the models. Also some enhancements cannot be done without completely redesigning entities. In this paper we propose to separate the existence aspect of an entity in one process. A second proposal is to model relationships (i.e. aspects comon to two or more entities) between entities explicitly using entity‐relationship notation. In this way, more maintainable specifications will be

ISSN:1040-550X    

DOI:10.1002/smr.4360020106

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThis case study demonstrates how simple changes in the way maintenance is managed can result in significant benefits, improving productivity and performance.It describes the work carried out by a major U.K. services organization and was contracted to provide support and maintenance services for one of their key business systems.

ISSN:1040-550X    

DOI:10.1002/smr.4360020107

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

ISSN:1040-550X    

DOI:10.1002/smr.4360020108

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

ISSN:1040-550X    

DOI:10.1002/smr.4360020101

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY