Non-Functional Requirements – Maintainability
We have discussed the nonfunctional requirements for extensibility in our earlier posts. Now we turn to others in the nonfunctional list of requirements. Today we are going to consider maintainability. Maintainability is the measure of ability to successfully repair or fix the product after manufacturing, usually in the field, and over time.
For manufacturing entities, many of the maintainability requirements are born out, at least in part, by the manufacturing and assembly environment of the customer organization. The Design for Assembly (DFA) and Design for Manufacturing (DFM). The building of the product with ease will frequently translate into the maintainability requirements. That is not to say all will. The manufacturing line will often have specialized tools and conditions that ensure the long-term and repeatable production of the product. For example, the modular approach we take to manufacturing the system that may arise from our DFMA work will also likely help with the maintainability of the product in the field. So too does the use of standard parts rather than custom built.
However, the consideration of the aftermarket maintainability is not equal to the requirements from the manufacturing portion of the product, though there is some measure of congruency with the manufacturing. For example, the sterile and well-controlled manufacturing environment may bear little resemblance to the field environment. Some of those modules defined from the DFMA work may not be readily maintainable in this field environment. If there are a variety of modules (subassemblies) involved with the product a means must be made to account for these various part number’s and connect these to the particular top level part number or system. In the automotive industry, this is so important that there is frequently a separate group that will be responsible for the requirements associated with maintainability.
Those difference between manufacturing and the field service capabilities and needs of the organization can be conflicting and contentious. Working through these requirements requires identifying areas of conflict and effective resolution. Manufacturing and the ability of the aftermarket to maintain the product may be important to the project. If that is the case, we have to find ways to meet both of these objectives.