New-Tech Europe Digital Magazine | May 2016

A Recipe for Embedded Systems

Adam Taylor, e2v

ngineers never lose sight of the need to deliver projects that hit the quality, schedule and budget targets. You can apply the lessons learned by the community of embedded system developers over the years to ensure that your next embedded system project achieves those goals. Let’s explore some important lessons that have led to best practices for embedded development. THINK SYSTEMATICALLY Systems engineering is a broad discipline covering development of everything from aircraft carriers and satellites, for example, to the embedded systems that enable their performance. We can apply a systems engineering approach to manage the embedded systems engineering life cycle from concept to end-of-life disposal. The first stage in a systems engineering approach is not, as one might think, to establish the system requirements, but to create a systems engineering management plan. This E

(for example, EMI and EMC). Within a larger development effort, those requirements will be flowed down and traceable from a higher-level specification, such as a system or sub- system specification (Figure 1). If there is no higher- level specification, we must engage with stakeholders in the development to establish a clear set of stakeholder requirements and then use those to establish the embedded system requirements. Generating a good requirement set requires that we put considerable thought into each requirement to ensure that it meets these standards: 1. It is necessary. Our project cannot achieve success without the requirement. 2. It is verifiable. We must ensure that the requirement can be implemented via inspection, test, analysis or demonstration.

plan defines the engineering life cycle for the system and the design reviews that the development team will perform, along with expected inputs and outputs from those reviews. The plan sets a clear definition for the project management, engineering and customer communities as to the sequence of engineering events and the prerequisites at each stage. In short, it lays out the expectations and deliverables. With a clear understanding of the engineering life cycle, the next step of thinking systematically is to establish the requirements for the embedded system under development. A good requirement set will address three areas. Functional requirements define how the embedded system performs. Nonfunctional requirements define such aspects as regulatory compliance and reliability. Environmental requirements define such aspects as the operational temperature and shock and vibration requirements, along with the electrical environment

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