Understanding flow in software development: Economics, process, psychology

Flow in software development refers to the movement of work through a system and encompasses both process efficiency and the psychological state of developers, optimizing it is crucial for improving software delivery. Don Reinertsen's work highlights the economic implications of flow, emphasizing that delays and queues in development have quantifiable costs that impact business value. Flow efficiency measures the ratio of active work time to total elapsed time, and low percentages indicate systemic flow issues often caused by excessive waiting times for reviews or approvals. High utilization of resources like developers can reduce flow due to the cognitive cost of task-switching, which supports the need for managing work in small batches and maintaining some system slack. Addressing flow problems involves identifying and reducing bottlenecks, protecting uninterrupted work time, and managing queues to enhance feedback loops and reduce delays. Reinertsen's economic framework suggests that rapid feedback, small batches, and decentralized control are crucial for improving flow, as they help reduce risk, accelerate learning, and allow quicker responses to new information. Ultimately, the goal is to create an environment where work moves smoothly while maintaining sustainable practices, leading to higher quality outcomes, a more predictable delivery pace, and increased engineer satisfaction.