Reconfigurable Assembly Systems (RAS) offer the potential to enable rapid exchange of functional modules. There has however been little investigation into the planning of multiple system reconfigurations. The work proposes a capability-based approach; consisting of a Reconfiguration Methodology, supported by a Capability Model and Taxonomy. The Methodology focuses on multiple system reconfigurations and is based upon operator-oriented definition, thereby utilising existing knowledge and expertise. The Capability Model consists of Capability Identification and Comparison processes: by aggregating the results, capability and compatibility sets can be derived. Further, the Model has strong links to the Capability Taxonomy. The work describes the overall approach and key elements and provides a detailed example application in software using a simple multi-product test case. Key conclusions are drawn and future work outlined.