Similar Equipment Data
The data on mature equipments (with which the proposed design will be compared) must be as comprehensive as possible. The reliability that a particular piece of equipment is achieving in service must be determined, as well as the operational and environmental conditions of use associated with the reliability values. This is important because the same equipment can exhibit widely differing reliabilities in different environments and operating conditions. It is also important to establish, whenever possible, the development time scale and effort that was required to bring the reliability of a mature equipment to its current level. In general, data should include, where possible:
• The original reliability requirements.
• The extent of reliability design evaluation activities prior to hardware manufacture.
• The extent of reliability growth testing and the growth rate achieved during development.
• The rate at which design changes were schemed, manufactured and embodied for trial.
• Problem areas encountered during development and early in-service life.
• Analysis of main failure modes to avoid their recurrence.
The above data can then be used to assess the scale of the reliability programme associated with the reliability prediction.