Mission Requirements

Clarity in Mission Requirements is critical concept to successful solutions.

People in the solution delivery profession are generally informed about requirements.  Business Analysts, Software Developers, Solution Architects, Project Managers, know about the terms business requirements and system requirements, as well as functional requirements and non-functional requirements.

But seldom heard is the term ‘mission requirements’, which is interesting because it is the most essential of all the requirements of a system. Mission requirements are the raison d’etre of the system, its reason for being, the purpose for which the system is being produced.  All other requirements are subordinate to the mission requirements, and are derived from the mission requirements. 

The reason for the total absence of mission requirements in enterprises is undoubtedly because the word ‘mission’ itself is not part of the business vernacular.  One hears of the ‘vision’ for the enterprise, and its ‘mission’ but that is something quite different.

The phrase ‘mission requirements’ comes from the military and aerospace community.  A mission refers to the intention of the system, often a weapons system.  For example, a fighter plane’s mission is to shoot down enemy aircraft.  A Patriot missile battery’s mission is to shoot down incoming missiles. 

A system is assigned a mission because the super-system (the system which contains the system of interest), has objectives, and they perceive that to achieve the objectives, the system must be able to meet the mission requirements.

Mission requirements focus on the external system, not the system being built.  It is no surprise that mission requirements are measured using metrics called ‘Measure of Effectiveness’ .  This is about how well the solution is impacting the super-system and helping it achieve its objectives.

Think about a car.  A car with a top speed of 100mph.  It is impossible to say whether such a car is suitable or not without considering the mission for which it will be used, the part it will play.  If the car is to be used for transporting kids to and from school, then it’s perfectly suitable.  If it’s to be used to win a race, then it’s probably inadequate.

There is a hierarchy of requirements, and not the simple categorisation into just two: business,  and system requirements, is not rigorous enough. 

At the top of the hierarchy is the mission requirements.  All other requirements are derived from it, or in support of it.  These requirements must be set out very clearly.