Document performance requirements

As stated previously, ensure that performance requirements are well known and clearly documented from the outset and that they are not ignored until late in the development lifecycle.

Common business performance criteria are:
  • Processing Rate (commonly referred to as transactions per second or TPS)
  • Processing cost (a common z/OS concern - MIPS - million instructions per second)
  • Latency
Note: For each criteria it is important to document the exact scope of the requirement. For example in relation to latency, is it specific to the whole end to end of the process or is there a key response that must occur within the latency period, make sure there is sufficient detail to prevent ambiguity.