15.1
Chapter 15
Lean synchronization
The Illustrated London News Picture Library
15.1
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.2
Lean operations
Operations
strategy
Design
Lean operations
Improvement
Planning
and control
The market requires…
specified time, quantity and
quality of products and
services
The operation supplies…
the delivery of products
and services only when
needed
15.2
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.3
Key operations questions
In Chapter 15 – Lean synchronization – Slack et al.
identify the following key questions:
• What is lean synchronization?
• How does lean synchronization eliminate waste?
• How does lean synchronization apply throughout the
supply network?
• How does lean synchronization compare with other
approaches?
15.3
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.4
Lean operations
‘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, more
dependable, produces higher quality products
and services and, above all, operates at low
cost’.
15.4
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.5
Lean operations (Continued)
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.
15.5
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.6
Lean operations (Continued)
JIT material flow
Traditional approach
Stage A
Buffer
inventory
Stage B
Buffer
inventory
Stage C
JIT approach
Orders
Stage B
Stage A
Deliveries
15.6
Orders
Stage C
Deliveries
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.7
Lean operations (Continued)
Traditional
approach
Lean
approach
Focus on highcapacity utilization
Fewer stoppages
More stoppages
because of
problems
More production
at each stage
High inventory
means less chance
of problems being
exposed and solved
Extra production
goes into inventory
because of continuing
stoppages at earlier
stages
15.7
Focus on producing
only when needed
Lower-capacity
utilization, but
Low inventory so
problems are
exposed and
solved
No surplus
production goes
into inventory
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.8
Lean operations (Continued)
The lean philosophy of operations
Eliminate waste
Involve everyone
Continuous
improvement
Lean as a set of techniques for managing
operations
Basic working practices
TPM
Design for manufacture
Set-up reduction
Operations focus
Total people involvement
Small, simple machines
Visibility
Flow layout
JIT supply
Lean as a method of
planning and control
Pull scheduling
Kanban control
Levelled scheduling
Mixed modelling
Synchronization
15.8
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.9
Inventories of materials. Information or customers have similar
characteristics
Of material
(queue of material)
Inventory
Of information
(queue of information)
Wastes customers’ time
Cost
Ties up working capital
Space
Quality
Needs storage space
Needs memory capacity
Defects hidden, possible Defects hidden, possible
damage
data corruption
Need waiting area
Gives negative perception
Decoupling
Makes stages
independent
Makes stages independent
Promotes job
specialization/
fragmentation
Utilization
Stages kept busy by
work-in-progress
Stages kept busy by work in Servers kept busy by
data queues
waiting customers
Coordination Avoids need for
synchronization
Less current information
and so worth less
Of customers
(queue of people)
Avoids need for straightthrough processing
Avoids having to match
supply and demand
Source: Adapted from Fitzsimmons, J.A.
15.9
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.10
Waste
Activities that consume time, resources and space, but
do not contribute to satisfying customer needs.
• Over-production
• Waiting time
• Transport
• Process
• Inventory
• Motion
• Defectives.
15.10
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.11
Waste (Continued)
Over-production
• Make more than is required by the customer, or to make
it earlier than required.
– Taking multiple copies of the document which are not
required.
Waiting time
• Any delay between when one process step/activity ends
and the next step/activity begins.
– Waiting for a manager to approve an application.
15.11
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.12
Waste (Continued)
Underwriting
Transport
• Movement of work between
departments or offices that do not add to
the value of the product or service.
LPC
IT
– Multiple approvals across different
departments.
(Over) Processing
Operations
2
Operations
1
• Adding more value to a service or product than
customers want or will pay for.
– Capturing extra information from the customer which is
not used.
15.12
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.13
Waste (Continued)
Inventory
• More materials or information on hand than is currently
required.
– 100 applications waiting together for data entry.
Motion
• Needless movement of people.
• While ‘transportation’ refers to the movement of the
work, ‘motion’ involves movement of workers.
– Running to a printer on a different floor for a printout.
15.13
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.14
Waste (Continued)
Defects/Inspection
• Any aspect of the service that
does not conform to customer
needs.
– Incorrect customer details
captured in the system.
15.14
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.15
Some daily examples
Activity
Waste Category
• Making extra copies, just in case
• Over-production
• Document movement between departments
• Transport
• Supervisory approval delays
• Waiting
• Files waiting to be worked on
• Inventory
• Multiple calls to the customer for same issue
• Over-production
• Incorrect customer address
• Defect
• Cupboard full of office supplies
• Inventory
• Capturing additional fields in the system
• Over-processing
• Running for photocopier to other floor on building
• Motion
• Incorrect processing of salary
• Defect
• Customer on hold
• Waiting
• Forms moving different locations
• Transport.
15.15
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.16
Lean operations – The 5Ss
• 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.
15.16
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.17
Sort (Seri)
• Eliminate all unnecessary items!!
• Unnecessary refers to those things that are not needed
for current work.
Keep only things that are required in doing the job
15.17
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.18
Straiten (Seiton)
• Arrange items so that they can be found quickly by
Anybody, Anywhere, Anytime. Items should be easy to
find, easy to use and easy to put away.
• Tools
– Colour Coding, Signboards, Labeling.
Keep things in Order
15.18
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.19
Shine (Sieso)
• Everything is clean, neat, tidy and ready to use.
• Tools
– Five-Minute Shine
– Cleaning and Inspection checklists
– Checklist of activities needing maintenance
e.g. the ‘5-second stapler’ test!
A clean work place enhances health and productivity
15.19
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.20
Standardize (Seiketsu)
• To prevent setbacks in the first 3 pillars (Sort, Set In Order
and Shine)
• Tools
– Best Practice documentation and sharing
– SOPs documented and posted
– Checklists & job cycle charts.
15.20
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.21
Sustain (Shitsuke)
• To make 5Ss a habit in the way we do our day-to-day
activities
• Tools
–
–
–
–
–
5-S contests
Visual management boards showing 5-S audit
Slogans
Handbooks
Poka Yoke!
Make 5 S a habit
15.21
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.22
‘Value stream’ mapping
• ‘Value stream’ mapping focuses on value-adding activities
and distinguishes between value-adding and non-valueadding activities. It is similar to process mapping but
different in four ways:
– It uses a broader range of information than most process maps.
– It is usually at a higher level (5–10 activities) than most process
maps.
– It often has a wider scope, frequently spanning the whole
supply chain.
– It can be used to identify where to focus future improvement
activities.
15.22
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.23
Waste is a large part of most processes
Mapping the Value Stream – Example
High-level process steps for a loan application process
High-level process steps
Acquire
the customer
Prepare
application
Process
application
Advise
customer
Disburse
funds
Step-by-step activity analysis for value-add to our customer
Activities which add value to the customer: e.g. the credit decision
Activities which don’t add value to the customer but are required by regulation: e.g. KYC
Activities which neither add value nor are required by regulation: e.g. carrying files from one
desk to another
Actual value-add activity may only be 1 –10% of the total process time.
15.23
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.24
Value Stream Map for an industrial air-conditioning installation
service
T/T = Task time
TTT = Total throughput time
VAT = Value-added time
C/T = Cycle time
Sales
office
Operations
planning
Forecasts
Cash
management
Invoice
status
Job-tracking confirmations
Survey
Wait in
branch
Wait for
assembly
T/T = 0.5
Avail = 100%
C/T= 10
T/T = 0.5
Avail = 100%
C/T= 30
15.24
30 mins.
Install
Frame
Ship to
Wait for
branch and
installers
wait
T/T = 0.75
T/T = 5.0
Avail = 100%
Avail = 100%
C/T= 17
C/T= 12.5
48 hrs.
96 hrs.
58 hrs.
30 mins.
Assemble
Order
Completion
confirmation
5 hrs.
48 hrs.
60 mins.
T/T = 0.75
Avail = 100%
C/T= 35
TTT = 258 hrs
60 mins. VAT = 8 hrs
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.25
Delivering smaller quantities more often can reduce
inventory levels
Inventory
levels
Inventory
levels
15.25
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.26
Waste (muda)
Which of these symbols signify non-value-adding activities?
Activities
Operation
Movement
Types of waste
• Over-production
• Waiting time
• Transport
Inspection
Delay
Storage
•
Process
•
Inventory
•
Motion
•
Defective goods
 Influencing the throughput efficiency
15.26
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.27
The problem with inventory
Productivity
problems
Reduce the level of
inventory (water) to
reveal the
operations’ problems
WIP
Defective
materials
Scrap
Rework
Downtime
WIP
Defective
materials
Productivity
problems
Scrap
Rework
Downtime
15.27
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.28
Small machines
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’.
Changeovers
Inventory
levels
Time
15.28
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.29
Small machines (Continued)
Using several small machines rather than one large one
allows simultaneous processing, and is more robust and
more flexible.
Inventory
levels
Time
15.29
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.30
Flow principle
• A process consists of 3 steps – A, B and C.
• It takes one minute to finish each step of the process (A, B and C).
Batch Flow (units processed in batches of 10)
• How much time will it take for 10 units to move through the process?
A
10 Minutes
B
+
10 Minutes
C
+
10 Minutes
= 30 Minutes
15.30
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.31
Flow Principle (Continued)
• A process consists of 3 steps – A, B and C.
• It takes one minute to finish each step of the process (A, B and C).
Continuous Flow (unit processed individually, that is, process
one, move one)
• How much time will it take for 10 units to move through the process?
A
B
C
1 Minute + 1 Minute + 10 Minutes = 12 Minutes
15.31
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.32
Single-piece flow
• Traffic lights – typical batch processing
– Flow of traffic in batches may cause uneven loads
of traffic – traffic may jam on one side while no
vehicle come from other directions.
• Roundabout – single-piece flow
– Traffic flows as soon as there is capacity in the
roundabout piece by piece.
15.32
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.33
Levelled scheduling equalizes the mix of products
made each day
Over an eight-day period, need to make 1200 of A
400 of B
400 of C
Scheduling in large batches, where batch size A = 600, B = 200, C = 200
250 A
250 A
100 A
50 B
150 B
200 C
600 A
250 A
200 B
200 C
250 A
100 A
50 B
150 B
200 C
600
A
200 B
200 C
Every day, the schedule needs to be calculated. Each day can be different
15.33
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.34
Levelled scheduling equalizes the mix of products
made each day (Continued)
Over an eight-day period, need to make 1200 of A
400 of B
400 of C
With levelled scheduling, where batch size A = 150, B = 50, C = 50
150 A
150 A
150 A
150 A
150 A
150 A
150 A
150 A
50 B
50 B
50 B
50 B
50 B
50 B
50 B
50 B
50 C
50 C
50 C
50 C
50 C
50 C
50 C
50 C
150 A
50 B
50 C
150 A
50 B
50 C
150 A
50 B
50 C
150 A
50 B
50 C
150 A
50 B
50 C
150 A
50 B
50 C
150 A
50 B
50 C
150 A
50 B
50 C
Every day is the same. Easy to notice if falling behind schedule
15.34
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010
15.35
Lean planning and control, or MRP, or both?
Complex
structures
Project
management
MRP
Lean and/or
MRP
Lean
Simple
structures
Simple
routings
15.35
Complex
routings
Slack, Chambers and Johnston, Operations Management, 6th Edition,
© Nigel Slack, Stuart Chambers, and Robert Johnston 2010