1. Lean operations and JIT
Chapter 15
Lean operations and JIT
Source: Tibbet and Britten

2. Lean operations and JIT
Operations strategy
Lean operations and JIT
The market requires … specified time, quantity and quality of products and services
Operations management
Design
Improvement
The operation supplies … the delivery of products and services only when needed
Planning and control

3. ‘The key principle of lean operations is relatively straightforward to understand: it means moving towards the elimination of all waste in order to develop an operation that is faster and more dependable, produces higher quality products and services and, above all, operates at low cost.’

4. Synonyms continuous flow manufacture high value-added manufacture
stockless production
low-inventory production
fast-throughput manufacturing
lean manufacturing
Toyota production system
short cycle time manufacturing
Source: Corbis/Denis Balihouse

5. JIT material flow Traditional approach JIT approach buffer inventory
stage A
stage B
stage C
JIT approach
orders
orders
stage A
stage C
stage B
deliveries
deliveries

6. JIT and capacity utilization
JIT approach
focus on producing only when needed
fewer stoppages
low inventory so problems are exposed and solved
no surplus production goes into inventory
lower capacity utilization, but
JIT and capacity utilization
Traditional approach
focus on high capacity utilization
more stoppages because of problems
high inventory means less chance of problems being exposed and solved
extra production
goes into inventory because of continuing stoppages at stages
more production at each stage

7. JIT definitions
JIT aims to meet demand instantly, with perfect quality and no waste
More fully:
Improved overall productivity and elimination of waste
Cost-effective production and delivery of only the necessary quantity of parts at the right quality, at the right time and place, while using a minimum amount of facilities, equipment, materials and human resources
JIT is dependent on the balance between the supplier’s flexibility and the user’s flexibility
JIT is accomplished through the application of elements that require total employee involvement and teamwork
Source: Empics
A key philosophy of JIT is simplification

8. The lean philosophy of operations is the basis for JIT techniques that include JIT methods of planning and control
The lean philosophy of operations
Eliminate waste
Involve everyone
Continuous improvement
JIT as a set of techniques for managing operations
Basic working practices
Design for manufacture
Operations focus
Small, simple machines
Flow layout
TPM
Set-up reduction
Total people involvement
Visibility
JIT supply
JIT as a method of planning and control
Pull scheduling
‘Kanban’ control
Levelled scheduling
Mixed modelling
Synchronization

9. The 5 S’s
Sort (Seiri) Eliminate what is not needed and keep what is needed.
Straighten (Seiton) Position things in such a way that they can be easily reached whenever they are needed.
Shine (Seiso) Keep things clean and tidy; no refuse or dirt in the work area.
Standardize (Seiketsu) Maintain cleanliness and order – perpetual neatness.
Sustain (Shitsuke) Develop a commitment and pride in keeping to standards.

10. Delivering smaller quantities more often can reduce inventory levels

11. influencing the throughput efficiency
Waste (muda)
Which of these symbols signify non-value- adding activities?
Activities:
Types of waste:
operation
over-production
waiting time
movement
transport
inspection
process
inventory
delay
motion
storage
defective goods
influencing the throughput efficiency

12. The problem with inventory
Reduce the level of inventory (water) to reveal the operations’ problems
WIP
Defective materials
productivity problems
Scrap
Rework
Downtime
WIP
Defective materials
Rework
Scrap
Downtime
productivity problems

13. Small machines
The conventional Western approach is to purchase large machines to get ‘economies of scale’.
These often have long, complex set-ups, and make big batches, quickly creating ‘waste’.

14. Using several small machines rather than one large one allows simultaneous processing, is more robust and is more flexible
JIT small machines approach:
easy to move (layout)
quick set-up
flexible scheduling options
cheaper tooling
fewer set-ups needed
planned maintenance easier
emphasis:
flexibility
economies of scope

15. Visible, enforced improvement
‘Traditional’ production systems often accept waste and use the insurance of all types of inventory
In JIT systems:
gradual reduction of inventory
identify exposed problems
eliminate these problems
repeat the cycle
emphasis:
continuous improvement in small steps, to expose waste and eliminate it

16. PERT MRP JIT and/or MRP JIT JIT, MRP, or both? complex structures
simple structures
MRP
JIT and/or
JIT
simple routings
complex routings

17. Key Terms Test Just-in-time (JIT)
A method of planning and control and an operations philosophy that aims to meet demand instantaneously with perfect quality and no waste.
Kaizen
Japanese term for continuous improvement.
Set-up reduction
The process of reducing the time taken to change over a process from one activity to the next; also called single minute exchange of dies (SMED) after its origins in the metal pressing industry.

18. Key Terms Test Single minute exchange of dies (SMED)
Alternative term for set-up reduction.
Andon
A light above a workstation that indicates its state: whether working, waiting for work, broken down, etc. Andon lights may be used to stop the whole line when one station stops.

19. Key Terms Test
Kanban
Japanese term for card or signal; it is a simple controlling device that is used to authorize the release of materials in pull control systems such as those used in JIT.
Levelled scheduling (Heijunka)
The idea that the mix and volume of activity should even out over time so as to make output routine and regular, sometimes known by the Japanese term ‘heijunka’.