The paradigm of forming and sustaining Collaborative Networks as environments that create Virtual Organisations (VOs) assumes that effective (and efficient) enterprise engineering (EE) capabilities and processes are available. However, these processes are only effective if they produce VOs which have sufficiently limited complexity, because as complexity grows, the VO’s behaviour becomes increasingly harder to predict under all circumstances. This paper proposes the use of EE methods based on Extended Axiomatic Design Theory to limit the complexity of VOs – and of the CN itself. We introduce process- and people capability maturity levels, whereupon higher maturity implies higher probability of success of CNs in creating and maintaining VOs, and success of the VOs themselves, and formulate strategies for capability-improvement, intended to achieve higher levels of EE maturity.