Knowledge-intensive administration and service activity has features favouring a particular architectural approach to business process integration. The approach is based on a process metamodel that extends the familiar input-process-output schema, and embodies the principle that the essential WHAT of a process is prior to any empirical and/or physical HOW. A structure of interrelated concepts can be derived from the metamodel. These can be used at logical level to define and analyze processes. They can also be implemented at a physical level—as an achievable and ideal integrated process architecture, or as a continuum of incremental control and integration improvements. Overall, the approach is to process what double entry is to accounting and the relational model is to data.