This task is optional. If Business Process Design is in scope Performance measurement is a critical, i.e. non-optional activity. The process key performance indicators are the indicators, parameters or process results that enable measurement on how well the process performs. Examples of such indicators are average elapsed time for a transaction, percentage of process exemptions, process costs. The key performance indicators describe which indicators are used and how these indicators are measured. Key performance indicators (KPIs) are usually typical for a particular industry or process type. If a reference model is used it may include key performance indicators. It is likely that these will be included as candidate performance indicators.