Petri Nets for Component-Based Software Systems Development

Abstract

The Software Engineering discipline was created to try to apply techniques and methods of others engineering disciplines to software systems development. To achieve this goal it was necessary to change the way software was developed, not only at code level, but also at the process level. Like in other engineering disciplines, one of the major objectives of software engineering is to develop artifacts in a systematic way. Several building block approaches were proposed and developed along the years. Nowadays one of the most researched and used approach are software components (Crnkovic and Grunske, 2007. Nierstrasz et al., 2002). Components are autonomous units with independent life cycle that represent an specific functionality. A component consists of functionality, interface and possibly other non functional characteristics. The development of bigger systems with components as building blocks is called Component Based Development (CBD). To make this possible it is necessary to adapt the traditional software engineering techniques and methods, or even defined new ones, to attend to specific CBD requirements. In the context of Component Based Software Engineering (CBSE) the objective is to define a set of practices that promotes the CBD. Formal methods improve the development process of software and hardware systems by helping designers to achieve dependability at different levels of abstractions such as requirements, specification, modeling and design. This is mainly due to the fact that the application of formal methods helps discovering and removing errors by performing automatic analysis and verification (Clarke and Wing, 1996). Petri nets (Murata, 1989), and more specifically Hierarchical Coloured Petri Nets (HCPN) (Jensen, 1992. Jensen, 1997) are a very powerful tool that has been widely studied and applied for the specification and analysis of complex concurrent systems (Donatelli and Thiagarajan, 2006. Kleijn and Yakovlev, 2007. Jensen, 2005. Jensen, 2006). It has a graphical representation that helps the design of complex software systems. There are several advantages of using a formal method in systems design such as, automatic simulation, proof of properties and unambiguous documentation. In the context of software engineering, the reuse of artifacts in the development of new software systems increases the productivity. Also, the reuse of artifacts that are well known to be correct is an effective way to increase the dependability on the system under development. Reuse is not restricted to pieces of source code, but it can be also be applied to