Model Based Systems Engineering: Fundamentals and Methods

8

Validating Requirements and Assumptions

8.1. Introduction

In this chapter, we will discuss requirement and assumption validation. We recall that the signification of the word “validation” depends on the standard or norm to which it subscribes. Here, we subscribe to the ARP4754A recommendation, which is the most developed standard concerning validation; consequently, in this chapter, the concept of “validation” only refers to the concepts of requirements and assumptions, but never to the physical systems themselves.

Figure 8.1. ARP4754A validation and verification processes connection

Therefore, validating a system does not make sense in the context of ARP4754A, and this option is fully justified by the following reasoning: to develop the right type of systems¹, it is “only necessary” that the set of all requirements characterizing it and the assumptions related to its environment be positively validated and that the systems produced with regard to its requirements and assumptions be positively verified in relation to its requirements and assumptions, that is to say compliant. The set of requirements and assumptions associated with a type of systems is the cornerstone in developing this type of systems.

First, we recall what the ARP4754A states about the validation process, as well as the goal and means that this recommendation advises and implements. We will then see how these ...