Lean Systems
operations systems maximize the value added by removing unnecessary activities & delays
Just In Time
customer demand can be met while eliminating all forms of waste and non-value-added activities and continuously improving value-added activities.
Muda and types (7)
Form of wast in JIT
o Overproduction
o Inappropriate processing
o Transportation
o Motion or Waiting
o Inventory
o Defects
o Under-utilization of employees
Benefits of JIT (4)
- Shorter customer wait times
- Higher employee productivity
- Higher utilization rates
- Lower inventory cost
Downsides of JIT
- Employee burnout, strain
- Lack of breaks or rest for employees
Lean Supply Chain
Close Supplier Ties and Small Batch Sizes
Close Supplier Ties (4)
- Low inventory levels mean frequent, small deliveries from suppliers
- Less tolerance for poor quality, late deliveries
- Shorter lead times = less safety stock
- Trust them to deliver, small frequent delivery
Small Batch Ties
- Small batch sizes reduce cycle inventory
- Reducing cycle inventory decreases holding/manufacturing costs
- Support uniform loading across workstations
Pull Method
production triggered by customer demand or order for products – Toyota Car Parts
Push Method
production is started in advance of order etc anticipation for predictable demand – Fries
Type of process and job using both push and pull
Assemble to Order - Subway
Workforce Flexibility
workers can handle variety of tasks and shift workstations to alleviate bottlenecks
Quality at the source
employees act as their own inspectors
Poka-yoke
Mistake-proofing method to reduce human error
Jidoke
Automation that prevents defects from moving forward in the production line
Andon
A visual/auditory signal to communicate the need for help to resolve a problem
Uniform Loading (2)
spread demand evenly across months and production system
Design your system so daily load on individual workstations and daily demand for resources is constant
Takt Time
Cycle time of process needed to match the rate of production to the rate of sales or demand
Heijunka:
Levelling of production by both volume and product mix
Mixed-model assembly:
type of assembly that produces a mix of models in smaller batches
Fives S’s:
Sort
Set In Order
Shine
Standardize
Sustain
Sort
separate needed from unneeded items, discard everything that is unneeded
Set In Order
arrange what is left, find place for everything and put in place
Shine:
clean and wash work area to help make problems visible
