Work-oriented development of interactive software tools. Understanding the work of software maintainers and making an interactive software tool for them: Dissertation

Work-oriented development is based on a developmental framework. Its nucleus is in the hierarchy of activities (work). At the lowest level, there are operations that are part of the daily working routines. Then there is the learning level where we learn how to do the work. At the highest level, there are activities, working structures, that constrain the learning in work. A change in operations can cause learning and further modify the activity that it is part of. A change in activity is likely to cause a change in operations. This framework is used in analysing the work of software maintainers and their use of tools. The evolution of maintenance is discussed at the activity level. The routine work assumption is discussed at the learning level. The operations in maintenance are classified and tied to the working practice. An ethnological study of the programmers (later concentrating on software maintenance) was made to search for the place of programming knowledge. The tacit nature of that knowledge led to the idea of reconstruction (in a simple form, reverse engineering). Rather than trying to save and preserve the explicit knowledge, the reconstruction tries to reconstruct the knowledge from the available sources. In most cases, the programming language source code is the most reliable source and the old documents are the least reliable. The reconstruction is likely to appear in the head of the programmer rather than explicitly. The interactivity of a tool is tied to the 'rational' use of the tool. The greater the interactivity, the more closely the tool supports the work. The work-oriented tool development process is interactive, reflecting the resulting tool. The process starts with a theoretical, historical, and empirical analysis of the work under study. Then it incrementally enhances the originally very simple tool according to the requests of the user. During the process, the interactivity of the tool gradually increases. The work-oriented development is based on a view that human beings develop in their work and every individual has much tacit knowledge that only waits for utilisation. The developmental framework treats the programmers in their development process, how they learn and extend their professional skills. The developmental framework differs from the approach used in the natural sciences. The human work is the main concern instead of computers and the algorithms in them. The software engineering tradition originated from a work breakdown problem but has lately adopted the view of the natural sciences.