Towards Arguing the Cost-effectiveness of Coloured Petri Nets

The contribution of this paper is to propose and justify two general rules that can help to argue the costeffectiveness of use of the formal modelling language Coloured Petri Nets (CPN): (1) Construction of CPN models should be explicitly based on high-quality documentation that software developers already produce; (2) Use of CPN models should be explicitly seen as prototyping. Rule (1) enables assessment of cost. We want to observe that the ratio of time used on CPN compared to time used on other documentation is small. Rule (2) enables us to argue benefit. Prototyping is seen as beneficial as witnessed by its wide-spread use and high acceptance in the software industry. We illustrate how the two rules can be complied with in the development of an elevator controller. We also make a more general comparison of CPN-based prototyping and traditional prototyping. Finally, we describe how a CPN model and a CPN-based prototype are used to argue for the correctness of the elevator controller.