Lecture 6 Flashcards
Single piece flow
is the movement of products or services through the unit at a time (as opposed to batch processing)
What does single piece flow ensure?
• It ensures employees are focused on the value-adding elements of rather than waste, waiting, transportation etc.
What does single piece flow smooth?
• It also smoothes the flow of the process creating a consistent workload ‘drumbeat’ which improves employee performance
Advantages of single piece flow
- Reduced lead time
- Eliminates over-production (the mother of all waste)
- Reduces inventory
- Identifies defects early within the process
- Provides agility to rapidly respond to changing customer requirements
Factors that prevent companies from acvhieving/ implementing single piece flow
- The type of demand
- Cost
- Layout
- Planning
- Resources
What needs to happen to single piece flow for it to be effective
it must be linked to other Lean improvements:
• The product changeover times must be short (as short as possible)
• Process volumes need to be linked to customer demand.
• The facility layout should support single piece flow (u-shaped cells/ layout)
• The layout should include in-process control (or inspection) to avoid defects being passed forward
• The product should be pulled through the system, not pushed
Parallel processing
is when processes happen at the same time e.g., in the grocery stores when different activities are going on. To reduce lead time (calendar time) process steps that are currently being completed in series can be re-engineered to work in parallel.
What are the elements required for parallel processing
- The customer (or the business) would value the reduction in lead time
- Only process steps which are independent of each other can be done in parallel
What does multi-skilling support?
supports flow because it ensures there are enough sufficient skilled employees to carry out the process
What does must-skilling improve?
improves quality because all team members are aware of up & down-stream processes & can immediately identify defects
Traditional layouts
- Complex flows of material & information
- Bottleneck steps
- Reduced vision and ownership of the total value chain
- Operators concentrate on islands of efficiency
- Reduces the value adding capability
Cell layouts
- Typically, u-shaped (no doubling back)
- Operations combines & single piece flow adopted
- The flow of materials become smoother
- There is no queuing between processes
- Throughput time is reducing
- Operators are trained in more than one task
Changeover time
the time between the last good item and the first good item after a product changeover
Quick changeover
the process used to reduce changeover times
The quick changeover process
- Observe & measure the current process
- Separate internal & external activities
- Convert internal to external activities
- Create parallel activities
- Minimize internal & external activities
- Implement the new process & validate
- Document the new process
- Chart changeover time
