RMQ Life Cycle

Every product, from the simplest to the most complex, passes through a sequence of phases during its life cycle. Though the exact terms used to describe each of these phases may vary from one company, organization or manual to the next, they typically include the same general periods of a product’s life: concept through development, production, operation and finally retirement. The table below describes the sequence of general phases in a product’s life.

Beginners to the reliability field quickly realize that there are a variety of RMQ practices used to model, estimate, test and/or analyze a system’s behavior in a particular use environment. In addition to understanding the differences between the various approaches, it is also important to know the appropriate situations to perform the various activities. For example, it wouldn’t make much sense to start testing the reliability of a design that has already been put in production, because any identified flaws in the design would be very costly to correct, not to mention the units that are already operating in the field. Of course there are exceptions under special circumstances, but RMQ activities are primarily performed during a specific phase of the product’s life cycle based on their purpose and the use of their results. The RMQ activities associated with the different life cycle phases are also identified in the table below. A review of this table should also provide an overview of the general reliability process, showing the sequence in which these activities are performed, and how the results from one analyses provide inputs for later considerations, testing and or analyses. Following this process, specifically by performing the RMQ activities during the appropriate phase of the system’s life cycle, helps to avoid costly oversights and ensure the production and fielding of a robust, reliable system.

Factors specific to each development effort (e.g., new product, experimental technology, unknown failure modes, etc.) typically dictate which activities should be performed. However, those that are selected should be performed during the appropriate life cycle phase as identified in the above table.