James Womack and Daniel Jones are well-recognized contributors to the lean-business movement. Lean Solutions is the consultants' fifth book together, following earlier works like Lean Thinking and The Machine That Changed the World, and springs as before from their keen interest in Japanese business methods and philosophy. What compels them to write yet another book, though, given the well-established literature on lean business?

The authors offer an intriguing description of their mission at the beginning of this latest book. Principles of lean design have in fact been adopted by many Western businesses, they acknowledge, and manufacturing quality has steadily risen as a result. Yet customers remain often dissatisfied with their experiences. The cause? To Womack and Jones, the answer rests in a myopic application of lean business principles: companies have successfully improved their manufacturing and product-development environments, but they have not had a large enough view of the overall customer relationship, and of the need for leanness in all aspects of companies' interactions with customers.

Put another way: in Lean Solutions, readers find a new and much broader conceptualization of how lean-business methods--which, to be fair to Womack and Jones, have evolved so that they can claim a global heritage as much as a Far Eastern one--might apply across entire customer experiences, rather than just manufacturing processes. The structure of Lean Solutions centers on 6 requests that the authors believe customers implicitly demand from their vendors: "Solve my problem completely; don't waste my time; provide exactly what I want; deliver value where I want it; supply value when I want it; and reduce the number of decisions I must make to solve my problems."

With a compelling mix of case studies, and illuminating thought experiments in industries ranging as widely as shoe manufacturing, health care delivery, auto repair, and grocery shopping, Womack and Jones walk readers through careful explanations of how lean thinking might be expanded beyond the factory floor to broader business problems. Lean Solutions isn't for all readers. It rests on an appreciation of the large cumulative effects that many small processes can have on business, and it requires patience from those who want to learn the secrets of lean business. --Peter Han