Boost projects with system engineering techniques

System engineering (SE) techniques can be applied in product development to boost the design cycle time and minimise risks during end customer development and integration. This application requires understanding complex end customer needs at the system level and then translating them into product requirements and system architecture.

This article describes system engineering that make use of form factor reference designs unique to the automotive industry, with real case examples including design and validation aspects. The automotive industry has unique aspects which add complexity and risk to product development and integration. For example, very long qualification cycles and stringent regulatory requirements. This complexity requires tighter risk management to prevent late findings and subsequent late product launches.

System Engineering is a multi-functional approach to engineering development with a strong focus on the holistic "big picture" of how the entire end product is brought together, deployed and supported. System engineering has been utilised and developed in various industries for many years and grown into its own specialisation within the engineering field. In the past, SE has been adopted only on large scale complex programs with multiple functional domains and multiple suppliers. An extreme example of a program of this magnitude is the International Space Station developed over time with NASA and other national space agencies. This system has multiple modules each with its own mechanical, aeronautical, electrical, thermal, structural, propulsion, and other systems that all must interact successfully.

Within the embedded community, products are typically considered as self-contained systems. However, modern embedded systems are often part of a larger system which must be considered in the design. Figure 2 illustrates the relationship of various sub-systems in a typical embedded design. Additionally, market forces demand faster-time to-market and more efficient development processes. System engineering offers tools to carefully define sub-systems, interfaces and overall integration.

Embedded systems are now reaching the complexity of larger systems. It is typical to have multiple boards, FPGAs, operating systems (OS) or other sub-systems that are integrated into embedded products. System engineering can minimise the amount ambiguity in the design phase and minimise the need for rework and redesign in the integration phases. This may reduce the need for painful escalations and "lines-down" product support during integration. Taking your customer's perspective on the system is an important step to understanding how SE can be applied to your product development.

Waterfall design methods
Traditional design typically uses the waterfall method. Generally this is a serial process that starts with a set of governing product requirements. These overarching requirements may come from many sources: competitive benchmarks, previous generation products, market studies or other sources. These requirements are used to develop a system architecture which drives development of sub-systems. Often these sub-systems are developed independently. Interfaces and sub-system boundaries where sub-systems interact are typically defined in the architecture specification (ie. hardware register definitions and software APIs). Once the sub-system design is completed, they are integrated into the larger system. There are debug and redesign cycles of varying magnitude until the final product is verified and ready for delivery. Figure 3 shows a typical design cycle using the waterfall method. The debug and redesign cycles may have multiple iterations based on the stability of the system architecture and the design quality.