Impediments to flow: Rethinking the lean concept of 'waste' in modern software development

Eliminating waste is a core principle of lean thinking. Despite the emergence of literature that applies lean in the software domain, an underlying analysis of this literature reveals the fundamental interpretation of waste has remained largely unchanged since its origins in manufacturing. Lean defines waste as any activity that does not directly add value as perceived by the customer. Software development is a creative design activity, not a production activity, and agile teams and organizations are more akin to complex adaptive self-organizing systems than repetitive production lines. Waste has different meaning in such systems. This paper reframes the lean concept of waste as impediments to flow in complex human systems. Drawing from ongoing research, this paper presents an updated categorization to describe the impediments faced by teams and organizations. The categories are extra features, delays, handovers, failure demand, work in progress, context switching, unnecessary motion, extra processes, and unmet human potential. These categories provide a foundation for helping teams and organizations to see, measure and reduce impediments to flow in their systems.