Does Design Pattern Support Easy Change Impact Analysis? - Focusing on the Command Pattern

Design patterns, a solution for the specific context and the problem, give benefits to us what a good design creates if we adequately use them in accordance with their purposes and principles. However, if we do not use them with inadequate purposes, using design patterns can be causes of increasing costs and decreasing maintainability and system performance. An industrial robot completes its given task through a series of hardware device’s primitive movements, controlled by an application using the APIs provided by specific hardware vendors. However, required movements of a robot change frequently because the given task changes often. This requires changes on hardware devices. As a consequence of this, APIs, controlling the hardware device change, and we also should modify the corresponding application. Therefore, an industrial robot software application should be designed such that it can easily trace hardware device’s change impacts on the application as well as it defines ordered composite primitive movements for completing the required task. This paper implements parts of an application that use hardware dependent APIs by using the command pattern and validates whether it support each change impact analysis.