Definition: The management discipline to constantly eliminate waste, improve response time, simplify the design of both products and processes, and thereby improve quality, customer service, and value. Continuous Improvement is a phrase suggesting that a process or product should always get better as knowledge about it and experience with it accumulates over time. It is specifically used in quality systems or management programs such as Total Quality Management, associated with the work of W. Edwards Deming, J, Juran, and Walter A. Shewhart, and is particularly evident at Toyota. 

Lean Enterprise is a management philosophy focusing on reduction of the 7 wastes, or Muda in Japanese (Over-production, Waiting time, Transportation, Over-processing, Inventory, Motion and Scrap) in manufactured products. By eliminating waste, quality is improved, production time is reduced, and cost is reduced. Lean "tools" include constant process analysis (kaizen), "pull" production (by means of kanban), and mistake-proofing (poka yoke). One crucial insight is that most costs are assigned when a product is designed. Often an engineer will specify familiar, safe materials and processes rather than inexpensive, efficient ones. This reduces project risk, that is, the cost to the engineer, while increasing financial risks, and decreasing profits. Good organizations develop and review checklists to review product designs. The key lean manufacturing principles:

• Perfect first-time quality – quest for zero defects, revealing & solving problems at the source
• Waste – eliminating all activities that do not add value & safety nets, maximize use of scarce resources
• Continuous improvement – reducing costs, improving quality, increasing productivity and information sharing
• Pull processing – products are pulled from the consumer end, not pushed from the production end
• Flexibility – producing different mixes or greater diversity of products quickly, without sacrificing efficiency at lower volumes of production
• Availability – when people, machines, product or processes are needed they are there, ready and able. Unplanned downtime, start up delays aren’t tolerated
• Building and maintaining a long term relationship with suppliers through collaborative risk, cost and information sharing arrangements

Lean is basically all about getting the right things, to the right place, at the right time, in the right quantity while minimizing waste and being flexible and open to change. Continuous Improvement is how you get Lean.