Resource: Andon Board Inventory Turns Level Loading Standard work Pull Based Production Quick Set up Time Reduction Work Cell (Cellular Manufacturing) Takttime Just in time (JIT) Terminology Continuous Flow Manufacturing (CFM): Heijunka, Hoshin planning, A 3 Thinking, Jidoka, Poka‐yoke , Kanban, Takt , Kaizen, Muda, Mura & Muri
Heijunka – production leveling
• Hoshin planning: a structured planning by focusing on a few critical problems at a time
• Jidoka: Ji – refers to the worker, do – refers to motion or work & ka– refers to action; together they refer to ‘automation with a human
• Muda: waste
• Mura: unevenness
• Muri: hard to do
• PDCA – plan, do, check, act
• Poka‐yoke – error proofing
• Kaizen – a small incremental improvement; involve everyone
• Kanban – an instruction to produce or supply something
• Takt – aligning work rate with the demand of the customer
Other Wasteful Issues
• Mura – is an unevenness in the work flow
– Heijunka (production leveling) is employed to have a mixed mode production/service so workers don’t have to strain have the day and coast the other
• Muri – means hard to do
– Caused by variation in production, poor job design, poor ergonomics, poor part fit, inadequate tools or fixtures, unclear job specification, etc.
Muda, Mura & Muri Relationship
• How to move 100 people to shore?
Muda (waste) – 100 trips
Mura (unevenness) ‐ 8 trips of 10 & 4 trips of 5
Muri (hard to do) ‐ 5 trips of 20
Lean – 10 trips of 10
• Hoshin kanri means:
– Shining metal or compass
– Ship in the storm on the right path
– Strategic policy deployment
• Essentially the nervous system of lean
– Short term – 1 year plan
– Long term – 3 to 5 year plan
• Use to identify and address critical business needs & identify the capability of the work force by aligning resources at all levels and applying the PDCA cycle to consistently achieve critical results
A 3 Thinking
• A one page story (11×17)
• A statement of objectives, goals, directions & problem solving
• Summarizes Kaizen circle activities
• Effective communication tool
• Four basic kinds of A3
– Hoshin planning
– Problem solving
– Current status
A visual control device in production area that gives the Current status of the production system and alert employees of emerging Problems.
The number of times inventory is consumed in a given Period.
The smoothing or balancing of the work load in all steps of A process.
Just in time (JIT):
A system for producing and delivering the right items at The right time in the right amount. Just in time is approximated when upstream Activities occur minutes or seconds before downstream activities, so one piece Flow is possible.
Continuous Flow Manufacturing (CFM): A process whereby material moves one piece at a time, at the rate determined by the needs of the customer, in a Smooth and uninterrupted sequence and without WIP (Work in process Inventory)
The available production time divided by the rate of customer Demand. For example, if customer wants 480 cars per day, and the factory Operate at 960 minutes per day, the takttime is 2 minutes. In a CFM, or lean Manufacturing process, it is desirable to make cycle time = takttime.
A precise description of each work activity, specifying Cycle time, takttime, the work sequence of specific tasks, the minimum inventory Of parts needed to conduct the activity
Work Cell (Cellular Manufacturing)
The ideal production process set up for lean operation is a ‘one piece flow work cell’
Pull Based Production
Pull based production system means ‘demand driven’production system. The pull based production system is modeled after the supermarket shelf replenishment operation. In the supermarket shelf, there are lots of goods, such as milk,eggs, orange juices that are ready for customers to pick up. The customers ‘pull’the goods from the shelf, then depending on how many items are taken away, the inventory person in the super market will ‘refill’the same amount of items by ‘pulling’them from the warehouse, then the warehouse person will order roughly the same amount of items that are ‘pulled’from warehouse.
The opposite of pull based production is ‘push’based production. The key feature for the push based production is that the direction of information flow is the same as that of material flow. In push based production, each work stop will send the work to down stream of the operation, that is, push the work downstream, without considering whether the down stream can make use of it. Typically, activities are planned centrally butdo not reflect actual conditions in terms of idle time, inventory, and queues.
Quick Set up Time Reduction
When one piece flow and cellular manufacturing system are used, it is very important that the setup time needed from producing one type of product to another type of product should be greatly reduced. Otherwise, the production system will be overwhelmed by frequentlong change over times from one type to the next. Toyota production system developed many quick setup time reduction techniques. However, the key idea is to divide the setup time into two categories of elements, one is called internal elements, the other is called external elements. The internal elements arethe actions needed in the setup where the regular production has to stop. The external elements are the actions needed in the setup where the regular production does not have to stop. The key strategy in quick setup time reduction technique is to redesign the work elements in set up so that overwhelming amount of setup work are done externally, that is, without production stoppage.