Measurement for the management of software maintenance

This thesis addresses the problem of bringing maintenance, in a commercial environment, under management control, and also increasing the profile of maintenance in a corporate picture, bringing it onto a par with other components of the business. This management control will help reduce costs and also the time scales inherent in maintenance activity. This objective is achieved by showing how the measurement of the products and processes involved in maintenance activity, at a team level, increases the visibility of the tasks being tackled. This increase in visibility provides the ability to impose control on the products and processes and provides the basis for prediction and estimation of future states of a project and the future requirements of the team. This is the foundation of good management. Measurement also provides an increase in visibility for higher management of the company, forming a basis for communication within the corporate strategy, allowing maintenance to be seen as it is, and furnished with the resources it requires. A method for the introduction of a measurement strategy, and collection system, is presented, supported by the examination of a database of maintenance information collected by a British Telecom research team, during a commercial software maintenance exercise. A prototype system for the collection of software change information is also presented, demonstrating the application of the method, along with the results of its development and the implications for both software maintenance management and the technical tasks of implementing change

A software maintenance method based on the software configuration management discipline

Software maintenance has until recently been the neglected phase in the software engineering process, despite the fact that maintenance of existing software systems may account for over half of all efforts expended by a software organization. Research into software maintenance, compared to other phases of the software engineering process is rare. Moreover, it is widely accepted that current software maintenance methods and techniques are unable to cope with the complexity inherent in maintaining software systems. This thesis is concerned with the development of a method, named Configuration Management Formalization for Maintenance (COMFORM), designed for the maintenance of existing software systems. COMFORM provides guidelines and procedures for carrying out a variety of activities performed during software maintenance. It accommodates a change control framework, around which the Software Configuration Management discipline is applied. Redocumentation is another problem tackled by COMFORM, which gathers together the documentation necessary to improve the maintainability and quality of existing software systems. This is achieved by the use of forms representing the output of each phase of a proposed software maintenance model. The information obtained by filling in forms is formalized according to a data model, which provides a common basis for the representation of the method's functionality. Finally, a prototype of COMFORM has been implemented, so that the procedures and guidelines set up by the method can be enforced and followed by its users

Inverse software configuration management

Software systems are playing an increasingly important role in almost every aspect of today’s society such that they impact on our businesses, industry, leisure, health and safety. Many of these systems are extremely large and complex and depend upon the correct interaction of many hundreds or even thousands of heterogeneous components. Commensurate with this increased reliance on software is the need for high quality products that meet customer expectations, perform reliably and which can be cost-effectively and safely maintained. Techniques such as software configuration management have proved to be invaluable during the development process to ensure that this is the case. However, there are a very large number of legacy systems which were not developed under controlled conditions, but which still, need to be maintained due to the heavy investment incorporated within them. Such systems are characterised by extremely high program comprehension overheads and the probability that new errors will be introduced during the maintenance process often with serious consequences. To address the issues concerning maintenance of legacy systems this thesis has defined and developed a new process and associated maintenance model, Inverse Software Configuration Management (ISCM). This model centres on a layered approach to the program comprehension process through the definition of a number of software configuration abstractions. This information together with the set of rules for reclaiming the information is stored within an Extensible System Information Base (ESIB) via, die definition of a Programming-in-the- Environment (PITE) language, the Inverse Configuration Description Language (ICDL). In order to assist the application of the ISCM process across a wide range of software applications and system architectures, die PISCES (Proforma Identification Scheme for Configurations of Existing Systems) method has been developed as a series of defined procedures and guidelines. To underpin the method and to offer a user-friendly interface to the process a series of templates, the Proforma Increasing Complexity Series (PICS) has been developed. To enable the useful employment of these techniques on large-scale systems, the subject of automation has been addressed through the development of a flexible meta-CASE environment, the PISCES M4 (MultiMedia Maintenance Manager) system. Of particular interest within this environment is the provision of a multimedia user interface (MUI) to die maintenance process. As a means of evaluating the PISCES method and to provide feedback into die ISCM process a number of practical applications have been modelled. In summary, this research has considered a number of concepts some of which are innovative in themselves, others of which are used in an innovative manner. In combination these concepts may be considered to considerably advance the knowledge and understanding of die comprehension process during the maintenance of legacy software systems. A number of publications have already resulted from the research and several more are in preparation. Additionally a number of areas for further study have been identified some of which are already underway as funded research and development projects