What is lean manufacturing?
a summary from McKinsey article: Goland, Hall and Clifford, First National Toyota, Nov 1998
Characteristics of lean manufacturing
Lean manufacturing was developed by Toyota
- to optimize production - by eliminating waste.
- building quality into manufacturing processes + recognizing the importance of cost reduction.
four defining characteristics:
to banish seven types of waste:
- unnecessary motion,
- waiting (for parts or for a machine to finish its cycle),
- excess inventory, and
- inessential transportation.
- spotting waste and
- figuring out ways to prevent it lies with .
- Spread the solution quickly within the organization
Continuous quality assurance.
NOT - inspecting work after it is completed and then performing any necessary rework,
DO - build in quality assurance at every step in the process.
In some cases, frontline workers have the authority to stop a production line if they see it putting out substandard products.
- supported by standard-ized work instructions that prevent differences in execution and
- rigorous maintenance procedures that minimize breakdowns and other hiccups in machine performance.
Just in time (JIT)
- supply each process with
- right quantity
- right item
- right time
- normally associated with external suppliers, but can extends to internal functions.
- Central idea: continuous flow
- elimination of stagnation in and between process steps -->
- minimize in-process inventory,
- avoid waste in transportation and motion, and
- improve feedback on defective output.
- Flexibility (reducing set-up times to the minimum)
- to promote effective capacity utilization
- cross-training employees to enable them to switch between assignments
- minimum inventory
- using tracking mechanisms to keep tabs on stock levels,
- avoiding bottlenecks
- to minimize work in progress (WIP), and timing deliveries to demand
Level productionLevel production is the end state achieved by a lean manufacturing system.
- Peaks and troughs in volume are minimized to ensure optimum capacity utilization,
- process is designed to enable the fastest possible throughput.
- (internal perspective) tasks are balanced between work stations and process steps
- so that utilization is maximized and
- overall cycle time kept to a minimum.
- check processing,
- loan processing, and
- call centers