This category can be considered the costs of consumer or user ownership. Included are the costs of sustaining operations, personnel and maintenance support, spares and repair parts, consumables, warehousing, shipping, configuration management, modification requirements, technical data changes, software maintenance and configuration control, and operating and maintenance personnel training. During this phase, data collection and tracking, customer site visits, failure analysis, and general integration issues constitute the majority of costs associated with maintainability. The maintainability aspects of engineering changes that occur during this phase must be evaluated.
Maintainability is important to O&M costs because it directly influences the ease and economy with which required maintenance can be
performed. Ease and economy translate to the number and qualifications of people required to support a product, the number and types of support equipment needed to perform maintenance, the time required to perform maintenance (cycle time and touch labor time4), and the degree of safety (of both the product and the people) with which maintenance can be performed. Although many other factors can affect the number of support personnel and other elements of operating and support costs, the level of maintainability designed into the product is an important driver of these costs. Indeed, if the maintainability engineer has done a good job, the O&M phase of the product's life cycle should reflect the benefits of a well balanced design: minimal downtime and low (affordable) ownership costs.
4The time that a maintenance person is actually doing work on the product.