Quality begins with the customer. But customers' views are continuously changing and standards are rising, so continuous improvement is required. Kaizen is dedicated to continuous improvement, in small increments, at all levels, forever (!). Everyone has a role, from top management to shop floor employees. Top management must allocate the resources and establish the strategy, systems, procedures and organisational structures necessary for Kaizen to work. Middle managers are responsible for implementing Kaizen. They must monitor performance of the continuous improvement programme, and ensure that employees are educated in the use of the necessary tools. Supervisors are responsible for applying Kaizen. They must maintain the rate of suggestions, coach, and improve communications at the workplace. And shop-floor employees must make suggestions, learn new jobs, use the tools, and generally participate in continuous improvement activities individually and in teams. Imai's book has several examples of how this philosophy is works its way down the organisational hierarchy in Japanese companies.

John Shook, speaking at the Lean Summit 1998, made the point that there are two types of kaizen, Flow Kaizen and Process Kaizen. Flow Kaizen is about value stream improvement, getting flow going, and should be a major concern of senior management. Process Kaizen is about the elimination of waste, which should be more the responsibility of the front line. Each level in an organisation has a responsibility for both, but the emphasis changes.

Imai believes that without active attention, the gains made will simply deteriorate (like the engineers' concept of entropy). But Imai goes further. Unlike Juran who emphasises "holding the gains", Kaizen involves building on the gains by continuing experimentation and innovation.

According to Imai there are several guiding principles. These include:

• Questioning the rules (standards are necessary but work rules are there to be broken and must be broken with time)
• Developing resourcefulness (it is a management priority to develop the resourcefulness and participation of everyone)
• Try to get to the Root Cause (try not to solve problems superficially)
• Eliminate the whole task (question whether a task is necessary; in this respect Kaizen is similar to BPR),
• Reduce or change activities (be aware of opportunities to combine tasks).