If we are to make logical decisions and choices in product and systems development, we need to have criteria to measure the value or relative importance of aspects of alternative proposals. This is an essential pre-requisite for part of trade studies. Both the client (customer, user) and the engineer have such measures, and these are related.
Measures of Effectiveness (MoE) represent the customer view, usually annotated and of qualitative nature. They describe the customers’ expectations of a product, project or system; the voice of the customer.
Measures of Performance (MoP) are the corresponding view of the engineer; a technical specification for a product. Typically Measures for Performance are quantitative and consist of a range of values about a desired point. These values are what an engineer targets when designing the product, by changing shape, materials and manufacturing process, so as to finally achieve the qualities desired by the customer.