Supply chain managers recognise that seamless supply chain operations require a high level of integration within and across organisations. Existing study and management focus have dealt with how to integrate supply chain activities across different organisations. However, it is not clear how a company should integrate supply chain functions within the company. One might assume that integration of the internal supply chain is easy to accomplish because top management has control over the functional areas. Yet, many companies suffer from supply chain disruptions due to internal coordination problems. As we started to investigate this issue we realised that the level of internal supply chain integration varies significantly from company to company. This discovery motivated us to take a systematic approach to investigating how companies integrate their internal supply chain. This study reports our findings with a focus on prescribing behaviours that managers can use to guide internal integration efforts.