We present an approach for designing organization-oriented multi-agent systems (MASs) to allow improvisation at run time when agents are not available to exactly match the original organizational design structure. Working with system components from an existing MAS organizational meta-model, OJAzzIC, the approach sets out five stages for the design process. We illustrate the design approach with an incident response scenario implemented in the Blocks World for Teams (BW4T) environment, and show how agents at runtime can improvise -for example they can adopt tasks even if those tasks do not precisely match a predefined role.