1. Lesson 3 Layout & Flow

2. Sandwich making
'If you were making a sandwich for a friend how would you do it?
'If you were making sandwiches for a whole group of friends who were due to arrive in an hour’s time, how would your process change?‘
'If you were making 5,000 sandwiches a day for a supermarket, how would you wish to organize the production system?'

3. Sandwich making
Sandwich for a friend - What kind of sandwich would they want (limited only by the availability of ingredients in the kitchen), when do they want it? (it could be made to order), and how much it could be customized (more salt and pepper)
Whole group/1hour arrival (You would butter all the bread together, standardize the products to some extent, and so on).
‘Making 5,000 sandwiches a day for a supermarket?'(would need to use an assembly line or process, etc.).

4. Volume & Variety
Layout and flow cannot be discussed without first considering :
The product volume and variety
The type of process to be employed
These factors are inextricably linked

5. How decisions might be connected (Slack2004)
Project process
Jobbing process
Batch process
Mass process
Continuous process
Fixed position layout
Process layout
Cell layout
Product layout
The physical position of all transforming resources
The flow of the operation’s transformed resources
Process type
Basic layout type
Detailed design of layout
Volume and variety
Strategic performance objectives
Decision 1
Decision 2
Decision 3

6. Volume & Variety Product volume – quantity of units produced
Product Variety – is the variation in products (SKU’s)
Product volume and variety is affected by the type of business and the market demand for products

7. Volume-Variety Dilemma Accepted continuum for processes
Low
VOLUME
High
High
Not possible?
VARIETY
Accepted continuum for processes
Not viable?
Low

8. Volume & Variety
Product volume and variety have a big influence on process design.
The two dimensions normally go together:
Low volumes operations normally have a high degree of product variety. [automotive component supplier]
High volume operations normally have a low degree of product variety.[canning plant]
The same organisation can have different parts of the operation organised differently – [large automotive OEM]
Volume/Variety is seen as having a large Influence upon the process type deployed

9. Volume & Variety
Process types in manufacturing are generally considered as:
Project Processes
Jobbing Processes
Batch Processes
Mass Processes
Continuous Processes
The volume/variety position points to the most appropriate process

10. Manufacturing Process Types
Volume
Low
High
Variety
Project
Jobbing
Batch
Mass
Contin-
-uous
Notice how process types overlap!
Process types are designed to cater for the volume /variety mix

11. Project Processes
One-off, complex, large scale, high work content “products” e.g. construction projects
Specially made, every one customized i.e. a project!
Defined start and finish: time, quality and cost objectives
Many different skills have to be coordinated
Fixed position layout, resources brought to product

12. Jobbing Processes Also deal with high variety / low volume
Very small quantities: “one-offs”
Specially made. High variety, low repetition e.g. bespoke suits
Skill requirements are usually very broad
Each job has to share resources with other jobs
Fixed position or process layout (routing decided by jobbers)

13. Batch Processes Higher volumes and lower variety than for jobbing
Standard products, repeating demand. But can make specials
Specialized, narrower skills
Set-ups (changeovers) at each stage of production
Can use process or cellular layout, has a predetermined planned routing

14. Mass (Line) Processes Higher volumes than Batch
Standard, repeat products
Low and/or narrow skills
No set-ups, or almost instantaneous ones
Cell or product layout: a fixed sequence of operations

15. Continuous Processes
Extremely high volumes and low variety: often single product
Standard, repeat products
Highly capital-intensive and automated
Few changeovers, if any, required
Difficult and expensive to start and stop the process
Product layout: usually flow along conveyors or pipes

16. The Product/Process Matrix
Low volume
Low standardization
INCREASING VARIETY
Multiple products
Higher volume
Few major products
High volume
High standardization
PRODUCT CHARACTERISTICS
INCREASING VOLUME
Machine tool maker
Custom furniture maker
Automobile factory
Petro- chemical refinery
Jumbled
flow
(jobbing)
Disconnected
line flow
(batch)
Connected
(mass)
Smooth flow (Continuous)
PROCESS CHARACTERISTICS
Random
(project)

17. Deviating from the ‘natural’ diagonal on the product-process matrix has consequences for cost and flexibility
Project
Jobbing
Batch
Mass
Continuous
Professional
service
Service
Shop
None
Less process flexibility than is needed so high cost
More process flexibility than is needed so high cost
The ‘natural’ line of fit of process to volume/variety characteristics
Manufacturing operations process types
Service operations process types
Variety
Volume 9

18. Layout and F low Layout decisions have to be carefully thought out:
Size and complexity of equipment involved
Cost
Resource and time
Disruption to production and customer service
Complex and ‘muddled’ production flows can evolve if not designed and monitored properly

19. Layout Product volume and variety dictate the process type selected.
Areas of overlap exist where more than one type could be applicable – in this case operational objectives are used to make decision: cost, flexibility, known future areas of growth etc.
There are four broad layouts
Fixed position
Process
Cell
Product

20. Layout
It is important to note that one process type does not mean one layout type.
There are normally choices associated with jobbing processes, batch processes and mass processes.

21. The nature of the basic layout types
Manufacturing B
asic layout
Service
process types
types
process types
Project processes
Project processes
Fixed
Professional
position layout
services
Jobbing processes
Process layout
Service shops
Batch pro
cesses
Cell layout
Mass
processes
Mass services
Product layout
Continuous
processes

22. Fixed Position Transformed resources do not move
Equipment and resources move to the product which is stationery.
Normally because product is too large, i.e. shipbuilding, aero-engine, power generators.
Or too delicate or fragile – heart transplant patient
Main problems associated with this type of operations are space and scheduling issues:
Adequate space for groups to work without interference
Storage for materials and equipment
Scheduling of material and people is key to FP success

23. Fixed Position Example
Case study exercise – ALSTROM
Pg 209
In groups of 2-3 discuss the set questions.
Question 2 should be answered in relation to performance metrics - Quality, Speed, Dependability. Flexibility and Cost

24. Alstrom Case Study
1. What factors at each site are likely to influence the layout?
Although the generators themselves will be relatively standard (though there are some variations) the installation of each will be slightly different where the generator interfaces with something else. The input of fuel, the output of generated electricity, and the way in which the generator is fixed to its foundations will all depend on the customer’s site. So, for example, the geometry of the site could be important. Very large pieces of the generator will have to be brought in and positioned in the site. If access to the site is restricted this may have to be done in a non-standard manner. Similarly, some of the services required by the product (compressed air, water, etc.) may not be available at the right place. These will also have to be provided.

25. Alstrom Case Study
2. Parts of the product are assembled in the factory and transported to the site. What advantage does this give the company?
The advantages to the company can be classed according to our normal five performance objectives as follows.
Quality – Assembling large parts of the generator at the factory ensures that the job will be done by skilled staff who can make sure that any small problems in assembly are solved at the point where there are the appropriate facilities. Assembling parts on the site introduces more variables which may undermine the quality of the product.
Speed – It will be faster to assemble parts in the factory using an appropriate layout than trying to do the same on the site where conditions are less predictable.
Dependability – Again, the relatively predictable conditions of the factory will allow assembly to be carried out to a schedule. Assembly on site is prone to disruption from the other tasks taking place on the site.
Flexibility – Standard parts, assembled at the factory, can be used for more than one customer. So, for example, if one part, when it gets to the site, is found to be unsatisfactory another one can be rushed to it at short notice.
Cost – Making many of the same part in the factory (even if the part is fairly large) is obviously cheaper than assembling everything on site.

26. Process Layout Resource types dominate layout decision
Similar process are located together – for convenience or utilisation
Parts are routed through the operation based upon their requirements
Flow patterns are different and complex
Control and visibility is also an issue
Example of use – production of aero-engine parts – many different processes involved.

27. Cellular Layout
Where all the required resources are available in one area to meet the processing needs.
Can be of the product or process layout type.
After completion the product may be finished or go to another cell.
Cells attempt to bring order to the product flow

28. Process Layout Cellular Layout

29. Product Layout Each product follows the same route
Can also be known as flow-line
Flow is clear predictable and therefore offers visibility and ease of control.
Products produced are standardised (although small variations are possible) – but flow route is the same.
Examples – car assembly, electronic goods etc.

30. Advantages and disadvantages
Fixed
Process
Cell
Product
position
layout
layout
layout
layout
Very high product
High product and
Can give good
and mix flexibility.
mix flexibility.
compromise.
Low unit costs for
high volume. A
dvantages
Product/customer
Relatively robust
Fast throughput.
not moved.
in the case of
Opportunities for
disruptions.
Group work can
specialization of
High variety of
result in good
equipment.
tasks for staff.
Easy to supervise.
motivation.
Can have low mix
Very high unit
Low utilization.
Can be costly to
flexibility.
costs.
rearrange existing
Disadvantages
Can have very
layout.
Not very robust to
Scheduling space
high WIP.
disruption.
and activities can
Can need more
be difficult.
Complex flow.
plant.
Work can be very
repetitive.

31. Next Week No tutorial sessions on Monday 15th October
Answer SAQ for Unit 1 - Lesson 3
Read Unit 1 lesson 4 of study guide
LAYOUT DESIGN TECHNIQUES – LINE BALANCING

32. Lesson 3 Self Assessment Questions

33. Lesson 3 Self Assessment Questions

34. Lesson 3 Self Assessment Questions

35. Lesson 3 Self Assessment Questions

36. Lesson 4 Layout Design Techniques:
Line Balancing

37. Last Week Discussed volume & variety
Processes – Project, Jobbing, batch, mass & continuous
Looked at layouts - Fixed position, cellular, process and product

38. This Week Layout Design Techniques Focus on Product layout Cycle time
Line Balancing

39. Product Layout
Transforming resources located for the convenience of the transformed resources
Product/customer/information follow a pre-arranged route
Sequence of activities matches the sequence in which process’s have been located

40. Detailed Design - Product Layout
Key decisions are concerned with ‘what to place where’ – in terms of what to allocate to each of the workstations.
This is termed line balancing
Other key questions are:
What cycle time is needed?
How many stages are needed?
How should the layout be balanced?
How should the stages be arranged?

41. Some definitions – (ch4 Slack)
Cycle time – the average time for units of output to emerge from the process
Throughput time – the time for a ‘unit’ to move through the process
Work Content – the total amount of work required to produce a unit of output
WIP – work in progress

42. Detailed Design - Product Layout
Cycle time = time available
No.of units to be processed
Suppose a bank is designing an operation to process mortgage applications. The number to be processed per week= 160 and the time available for processing = 40 hours
Cycle time = 40 = 1 hr = 15 minutes

43. Detailed Design - Product Layout
Number of stages req. = work content
required cycle time
Suppose the back in the previous example calculated the total
work content to process a mortgage application to be 60
minutes. Cycle time = 15 mins
Number of stages = 60 = 4 stages 15

44. Detailed Design - Product Layout
The previous example assumed that 15mins. of work time was allocated equally to each of the 4 stages.
This can be almost impossible in practice and some imbalance results
The effectiveness of the line balancing is measured by ‘balancing loss’
Balancing loss - is that proportion of the time invested in processing the product or service which is not used productively
Can lead to excessive stations being required

45. Calculation of Balancing Loss
Load
Stage
Cycle time = 2.5 mins
An ideal ‘balance’ where work is allocated equally between the stages
0.5 1
1.5 2
2.5 3 4
Load
Stage
Cycle time = 3.0 mins
2.3
2.5
2.2
3.0
But if work is not equally allocated the cycle time will increase and ‘balancing losses’ will occur
0.5 1
1.5 2 3
3.5 4
Work allocated to stage
Idle time
Calculating balancing loss:
Idle time every cycle =( ) + ( ) + ( )
= 2.0 mins
Balancing loss = 2.0
4 x 3.0 =
= 16.67% 9

46. The Plug and Play Excercise
STAGE 1
(10 secs)
STAGE 2
(50 secs)
STAGE 3
(15 secs)
STAGE 4
WHAT WAS THE CYCLE TIME?
HOW LONG DID IT TAKE TO MAKE THE FIRST PLUG?
HOW LONG DID IT TAKE TO MAKE THE LAST PLUG?

47. Timing diagram START OF PRODUCTION STAGE 1 10 20 30 40 50 60 70 80 90
100
110
120
130
140
150
160
STAGE 2 10 20 30 40 50 60 70 80 90
100
110
120
130
140
150
160
STAGE 3 10 20 30 40 50 60 70 80 90
100
110
120
130
140
150
160
STAGE 4 10 20 30 40 50 60 70 80 90
100
110
120
130
140
150
160
90 secs
50 secs
Start up
First Plug Produced
Second Plug Produced

48. Timing diagram END OF PRODUCTION STAGE 1 10 20 30 40 50 60 70 80 90
100
110
120
130
140
150
160
STAGE 2 10 20 30 40 50 60 70 80 90
100
110
120
130
140
150
160
STAGE 3 10 20 30 40 50 60 70 80 90
100
110
120
130
140
150
160
STAGE 4 10 20 30 40 50 60 70 80 90
100
110
120
130
140
150
160
50 secs
50 secs
50 secs
Last Plug Produced
Plug Produced
Plug Produced

49. Detailed Design - Product Layout
In Line balance calculations the initial start up situation is neglected and the cycle time is taken as the continuous rate of output
In this case 1 plug every 50 seconds
Note – it is the value of the longest activity (the bottleneck)
Using this value the line balancing loss can be calculated

50. The Plug and Play Excercise
STAGE 1
(10 secs)
STAGE 2
(50 secs)
STAGE 3
(15 secs)
STAGE 4
Idle time = (50-10)+0+(50-35)+(50-35)
= = 110 secs
Balance loss = (110/4*50)*100 = 55%
CYCLE TIME = 50 secs
WORK CONTENT = 90 secs 10 20 30 40 50 60 1 2 3 4 35
Stage secs Fit pins to plug
Stage secs Get plug from stage secs
Fit screws and cable retainer 30 secs
Take plug to Stage secs
Stage 3 15 secs Fit fuse and holder
Stage 4 15 secs Inspect and fit top cover

51. Karlstad Kakes Exercise
Consider Karlstad Kakes (KK) a manufacturer of speciality cakes which has recently obtained a contract to supply a major supermarket chain with speciality cake in the shape of a space rocket. It has been decided that the volumes required by the supermarket warrant a special production line to perform the finishing, decorating and packing of the cake. This line would have to carry out the elements in the precedence diagram shown on the next slide.
The initial order from the supermarket is 5000 cakes a week and the number of hours worked by the factory are 40 hrs/week

52. Element listing and precedence diagram for Karlstad Kakesb c d e f g h i
0.12 mins
0.30 mins
0.36 mins
0.25 mins
0.05 mins
0.17 mins
0.10 mins
0.08 mins
PRECEDENCE DIAGRAM a b c d e f g h i
Element De-tin and trim mins
Element Reshape with off-cuts mins
Element Clad in almond fondant mins
Element Clad in white fondant mins
Element Decorate, red icing mins
Element Decorate, green icing mins
Element Decorate, blue icing mins
Element Affix transfers mins
Element Transfer to base and pack mins
Total work content = 1.68 mins
No of units required cakes per week
Time available - 40 hrs per week
Cycle Time = 40x60/5000 = 0.48 mins
Number = work content/ cycle time
of stages
= 1.68/0.48 = 3.5 9

53. Allocation of elements to stages and balancing loss for Karlstad Kakesh i
0.12 mins
0.30 mins
0.36 mins
0.25 mins
0.05 mins
0.17 mins
0.10 mins
0.08 mins
Stage 1
Stage 2
Stage 3
Stage 4
MAXIMUM CYCLE TIME = 0.48 minutes
BUT MUST NOT COMPROMISE PRECEDENCE
Cycle time = 0.48 mins
Idle time every cycle = ( ) + ( ) + ( ) - 0 = 0.24 mins
Proportion of idle time per cycle = = 12.5%
4 x 0.48
0.42
0.36
0.48 9

54. Stage Arrangement How could the Plug and Play scenario be improved?
LONG AND THIN
Stage 1
Stage 2
Stage 3
Stage 4
One plug every 50 secs 10 50 15 15
LONG AND THIN
Controlled flow
More efficient – In real situation build operations are more complex. If each stage is performing a small part of the job can be made highly productive through the elimination of waste time
SHORT AND FAT
More flexible –
Volume -as demand varies shut down individual stages
Mix – Individual stages can specialise
Highly Robust – Any one stage fails other three carry on
Less Monotonous work 90
Stage 1 90
Stage 2
One plug every secs 90
Stage 3 90
Stage 4
SHORT AND FAT

55. Stage Arrangement Two main options: Long thin line Short fat line
Advantages of long thin:
Easy to manage flow of materials
Simplified material handling
More efficient operation
Advantages of short fat:
Higher mix flexibility
Higher volume flexibility
Higher robustness
Less monotonous work

56. Next Week Answer SAQ for Unit 1 - Lesson 4
ready for tutorial sessions on Monday 29TH October
LAYOUT DESIGN TECHNIQUES – PRODUCTION FLOW ANALYSIS

57. Tutorials Room RV307 Group 1 11-0 to 11-35pm Group 2 11-40 to 12-15 pm
See list to find out which group you are in

58. Line Balancing Exercise
SMC Ltd are developing a new process. The process has the following tasks and linkages.
Activity
Time (sec)
Predecessor A 12 B 8 C 10 D 16 E 20
B,D F 9 G 15 H 11
E,F,G I J K L 13
J,K
[adapted from Martinich, 1997]

59. Line Balancing Exercise
Your task is to :
Calculate the max cycle time if 1100 units are to be produced/8 hour day.
Calculate the minimum number of workstations.
Design a line that minimises the number of workstations.
Calculate the actual cycle time, production rate and efficiency

60. Self Assessment Questions

62. Line Balancing Case Study
Read the Weldon Case study on pgs
Working in groups of 2-3 answer the following questions:
How many people will be needed to assemble the product, during (i) yr1 qtr 1 and (i) yr2 qtr 4. Comment upon the sales forecast profile.
Design a layout for production during yr 1 qtr 1, consider both the short fat and long thin options. Discuss the arguments associated with each model.

63. Line Balancing Exercise
SMC Ltd are developing a new process. The process has the following tasks and linkages.[Martinich, 1997]
Activity
Time (sec)
Predecessor A 12 B 8 C 10 D 16 E 20
B,D F 9 G 15 H 11
E,F,G I J K L 13
J,K

64. Line Balancing Exercise
Your task is to :
Calculate the max cycle time if 1100 units are to be produced/8 hour day.
Calculate the minimum number of workstations.
Design a line that minimises the number of workstations.
Calculate the actual cycle time, production rate and efficiency

65. Product Flow Analysis

66. Product Flow Analysis Tutorial Example (1)

67. Product Flow Analysis Tutorial Example (2)
Allocate row values

68. Product Flow Analysis Tutorial Example (3)
(1)Sort by row
(2) Total columns

69. Product Flow Analysis Tutorial Example (4)
Sort by column

70. Product Flow Analysis Tutorial Example (5)