Software process white box modelling for FEAST/1

Abstract

This paper describes a high-level system dynamics model of a real-world software evolution process. This process is implementing embedded software elements of a defence system composed of hardware and software components. The model is one of the outputs of the FEAST/1 project, which is investigating the role and effect of feedback in the global software process. The simple feedback-based model, which has resulted from a top-down modelling approach, demonstrates the influence of the global process on the evolution of the software specification and implementation. Model outputs closely simulate actual and expected metrics for the real-world project. It is concluded inter alia that feedback external to a software production process may significantly influence that process.

Software evolutionary dynamics modelled as the activity of an actor-network

“…[8:125]. In our previous simulation models intended to represent the highest-level causal mechanisms producing observed patterns of commercial software evolution [3,17,19], these mechanisms have been highly abstracted, particularly with respect to the actions of individual people. Previous descriptions of the global software process have also tended to be based on an explicit or implicit division of these agents into 'active' people and 'passive' technical elements.…”

“…The influence of this mindset can be seen, for example, in [5], in which their Figure 1 shows a program surrounded by people, who are interacting with it but which are very obviously different sorts of things from the program itself. This mode of thinking is also implicit in our simulation models, in which we have sought to describe this process [3,16,17,19]. By way of contrast, Latour's actor-network theory (ANT) [7], an approach based on a sociological view of technological change, provides us with a viewpoint from which the effects of both human and technical participants on process characteristics and behaviour can be considered on a more equal footing.…”

“…As to how to obtain the relevant values, it will be necessary again to refer to experts' views as to how a specific process (or the process in general) works and reduce their opinions to quantified values. We have previously calibrated values for software processes based on expert opinion during the development of successful simulation models [3,19]. Finally, a mechanism for connecting the elements of the model into a network will need to be developed.…”

A policy investigation model for long-term software evolution processes

“…It is derived from ideas, structures and values from our previous software evolution simulation models. In particular, it incorporates feedback structures representing both the generation of new requirements (Chatters et al 2000) and the correction of faults in previously-implemented requirements (Wernick and Lehman, 1999 The model works as follows. The software process is viewed as a mechanism to convert requirements which need to be met into requirements which have been met and fielded to users.…”

“…First, developers are told that some requirements have not been met properly, typically due to bugs in the fielded software and/or mistaken interpretation of the users' requirements by the developers (cf. Wernick and Lehman, 1999). Secondly, new requirements arise due to the possibilities of additional uses of the system specifically enabled by the previously-fielded software (cf.…”