An Empirical investigation of software project schedule behavior.

Abstract

Two intensive, longitudinal case studies were conducted at IBM Hursley Park. There were several objectives to these case studies: first, to investigate the actual behaviour of the two projects in depth; second, to develop conceptual structures relating the lower-level processes of each project to the higher-level processes; third, to relate the lower-level and higher-level processes to project duration; fourth, to test a conjecture forwarded by Bradac et al i. e. that waiting is more prevalent during the end of a project than during the middle of a project. A large volume of qualitative and quantitative evidence was collected and analysed for each project. This evidence included minutes of status meetings, interviews, project schedules, and information from feedback workshops (which were conducted several months after the completion of the projects). The analysis generated three models and numerous insights into software project behaviour. The models concerned software project schedule behaviour, capability and an integration of schedule behaviour and capability. The insights concerned characteristics of a project (i. e. the actual progress of phases and milestones, the amount of workload on the project, the degree of capability of the project, tactics of management, and the sociotechnical aspects of a project) and characteristics of process areas within a project (i. e. waiting, poor progress and outstanding work). Support for the models and the insights was sought, with some success, from previous research. Despite the approach taken in this investigation (i. e. the collection of a large volume of evidence and the analyses of a wide variety of factors using a very broad perspective), this investigation has been unable to pinpoint definite causes to explain why a project will or will not complete according to its original plan. One `hint' of an explanation are the differences between the socio-technical contexts of the two projects and, related to this, the fact that tactics of management may be constrained by a project's socio-technical context. Furthermore, while the concept of a project as a distinct entity seems reasonable, the actual boundaries of a project in an organisation's `space-time' are ambiguous and very difficult to properly define. Therefore, it may be that those things that make a project difficult to distinguish from its surrounding organisation are interwoven with the socio-technical contexts of a project, and may be precisely those things that explain the progress of that project. Recommendations, based on the models, the insights and the conclusions, are provided for industry and research.