Towards Maintainable Architecture for Process Control Applications

Development of software systems utilizes only 20%-40% of the overall project cost; the rest is consumed by maintenance. Systems with poor maintainability are difficult to modify and to extend. Maintainability based risk is defined as a product of two factors: the probability of carrying out maintenance tasks and the impact of these tasks. The decision of adopting a single architecture over others should be verified through some pre-implementation analysis. This paper assesses different architectures for process control applications using a maintainability risk analysis. The paper illustrates the methodology using a simple example of a Gas Burner process control system.