Lean manufacturing is a management model which focuses on flow creation in order to deliver customers maximum value using the minimum resources necessary.
Creating flow centres on reducing the seven types of “waste” in manufactured products:
- Overproduction
- Waiting
- Transport
- Over processing
- Inventory
- Motion
- Defects
Eliminating waste improves quality and cuts both production times and costs. Lean tools include continuous analysis processes (called kaizen in Japanese), pull production (‘dissuasion and incentive’, in line with the Japanese term kanban) and failsafe elements and processes (poka yoke in Japanese), all from the perspective of gemba or value area.
One crucial aspect is that most of the costs are calculated at the product design stage. Engineers often specify known, reliable materials at the expense of other cheaper, more efficient ones. Although this reduces the risks of the project, or cost from the engineer’s perspective, it does so by increasing financial risks and lowering profits. Good organizations develop and review checklists to validate product design.
The key principles of lean manufacturing are:
- Perfect first-time quality: seeking zero defects, detection and solution of problems at source.
- Waste minimization: elimination of all activities that do not add value and safety nets, optimizing the use of scarce resources (capital, people and space).
- Continuous improvement: cost reduction, quality improvement, increased productivity and sharing information.
- Pull processes: product are pulled by the end customer, not pushed by production targets.
- Flexibility: produce different mixtures of a wide variety of products quickly, without sacrificing efficiency as a result of lower production volumes.
- Building and maintaining long-term relationships with suppliers, reaching agreements to share risk, costs and information.
The Lean approach is basically all about getting the right things in the right place at the right time in the right amount, minimizing waste, being flexible and remaining open to change.