The Principles of Product Development Flow: Second Generation Lean Product Development, by Donald Reinertsen. Celeritas Publishing, 2009.
Lean product development can be looked at as flow-based product development. Reinertsen draws on a variety of areas (economics, queue theory, control theory, the military) to explore the consequences for product development. The book is organized as 175 principles, organized into chapters by area. Here are a couple examples: “B2: The Batch Size Queueing Principle: Reducing batch size reduces cycle time”; “F8: The Cadence Batch Size Enabling Principle: Use a regular cadence to enable small batch sizes”. Each principle gets a page or two of explanations; the diagrams are plentiful and helpful. (For an introduction to the topic, I still recommend Reinertsen’s book Managing the Design Factory.)