Innovation as a process is related to the business viewed as a process. A process cannot be captured through the indicators of input/output, which are the most commonly accepted variables. Indicators of technological characteristics also limit the scope of measurement. Moreover, these indicators have often to be constructed upon non-gaussian variables that are not amenable to additive operations. This paper identifies a methodology to identify process innovation variables, some of which are gaussian and some are not. A few simple indicators are then constructed, using additive operations, upon both additive and non-additive variables. The additive variables yield generalisable indicators and the non-additive variables yield self-assessment type indicators. Both types can be used as process performance measurement systems. Examples of the values that these indicators take up, have been shown for nine firms. This vindicates the assumption on the applicability of these indicators.