The document discusses material flow and facility layout. It covers various layout types including fixed position, process, product, and cellular layouts. It also describes Richard Muther's 8 factors for facility layout analysis: material, machinery, labor, movement, wait, service, building, and change factors. Analyzing these factors helps determine layout requirements and restrictions for evaluating proposed layout solutions.

1. 10/08/2023
Material Flow
and facilities layout

2. Presentation
• Throughput or lead time are directly affected by the
where and how the processing and storage resources are
located in the factory.
• Plant layout is an activity that all companies are forced
to deal with sooner or later.
– It is important to be familiar with the methodologies used
to carry out these tasks.
• Cellular layouts - where labor and machines are grouped
in cells - will be explained in depth in the following
chapter.

3. TRANSFER
LINE
SPECIAL
SYSTEM
FLEXIBLE
MANUFACTURING
SYSTEM
MANUFACTURING
Cells
STD. AND GEN.
MACHINERY
VOLUME
HIGH
VARIETY
LOW HIGH
Production Systems Design

4. Introduction
• Factory layout improvements typically occur more than
one time during the factory’s life.
– The study of plant layouts seeks the optimal location for all
of the production resources.
• Tries to ensure that the economic impact of the project
on the enterprise will be as positive as possible.
• New plant layout must be as safe as possible and
satisfactory for the employees.
• It seems obvious that the optimal solution will be
unreachable or change routinely.
– Commitment between all the aspects is achieved.

5. Signs and reasons for a new layout
• Location change.
– Reasons to suggest a change of location of the factory.
• Location has become inadequate or antiquated.
• Factory expansion is impossible.
– Layout can be different if the company chooses a new
location by constructing a new building, versus utilizing an
existing facility.
• New building construction can allow for an ideal layout
because building functionality is the principle focus of
the building design.
– Use of the factory floor space should be better utilized.

6. Signs and reasons for a new layout
• Purchase new equipment
– New needs as well as technology improvements form the
basis of machinery purchase
• Finding the best location for the purchased equipment
can become a critical issue in making a “system”
perform as intended.
– Newly purchased incremental equipment is generally
placed in free space available.
• In some cases it is necessary to move machines to
create space.
• In other cases the new machine is located in a place
that promotes system efficiency.

7. Signs and reasons for a new layout
• Problems with materials flow
– This problem is generally derived from a problem
previously solved.
• Placing new equipment in available space in the plant
– The initial set-up costs decrease, but other problems
arise.
– Materials flow can be adversely affected by introducing
additional equipment.
• Equipment set up is typically done once, while the
materials flow is a continuing process.
– The analysis of this material flow can in most cases be
economically formulated.

8. Signs and reasons for a new layout
• High work-in-process (WIP).
– A good policy or layout in a given period of time may not
always produce good results forever.
– A measure of change in the company is the amount of
partially completed products (work-in-process).
• This should not be confused with a temporary situation
caused by a momentary increase in demand or stock
outages and/or surges.
– Slow changes in product variability can hide the negative
effects of the excessive work-in-process (WIP).

9. One-piece flow
• Before we begin exploring layout analysis
tools, it is important to clarify the
definition of production and transfer
batch even though both sizes are normally
the same.
– Production batch.
• Number of products included in the
customer order.
– Transfer batch (unit load).
• Amount of units that flows from one
machine to the next.
Thinking
revolution
The 5S
Standard
operations
One-Piece
flow
Poka-Yoke Jidoka
TPM
JUST IN TIME
Workforce
optimization
Visual
Control
Leveling
Production
Kanban
Multi-
functional
workers
SMED

10. One-piece flow
• Work-in-process decreases with a reduction in
the transfer batch size.
Thinking
revolution
The 5S
Standard
operations
One-Piece
flow
Poka-Yoke Jidoka
TPM
JUST IN TIME
Workforce
optimization
Visual
Control
Leveling
Production
Kanban
Multi-
functional
workers
SMED

11. One-piece flow
• Advantages of reducing the transfer batch
– Production feedback is faster.
– Lead time decreases.
• A reduction in the transfer batch increases the
material handling between sections.
• The ideal transfer lot size is called continuous
one-piece flow.
– Normally, a container size is considered unit load
flow.
• For example, a “1000-screws flow”, can be
used as “unit load flow”.
Thinking
revolution
The 5S
Standard
operations
One-Piece
flow
Poka-Yoke Jidoka
TPM
JUST IN TIME
Workforce
optimization
Visual
Control
Leveling
Production
Kanban
Multi-
functional
workers
SMED

12. One-piece flow
• One-piece-flow eliminates most of the causes
and effects outlined in the previous section.
– It is one of the Just-in-time tools.
• To come closer to an ideal one-piece-flow, the
material flow has to be minimized or
eliminated.
– If this is not possible, then the machines should
be located as close together as possible.
In order to improve the material flow, it is
typically necessary to analyze and change the
company’s layout.
Thinking
revolution
The 5S
Standard
operations
One-Piece
flow
Poka-Yoke Jidoka
TPM
JUST IN TIME
Workforce
optimization
Visual
Control
Leveling
Production
Kanban
Multi-
functional
workers
SMED

13. Main types of industrial companies
• In an open-market, there exists a multitude of different
products.
– food, cars, computers, bricks, cement, ships,...
• Each product has a specific manufacturing process.
• Analysis is conducted based on similarities
– Cars and washing machines? yogurt and soap?
• The grouping is based on the type of production facilities
that the companies uses.
– Industrial companies can be grouped into four sectors.
• Primary, Secondary, Tertiary and Service Sector.
– Secondary Sector (Process Industry and Consumption
Industry).
– Tertiary Sector (Production and Assembly factories).

14. Process industry
• Process focused industries
– The manufacture of the product
dictates the equipment and product
flow.
• Paper, wood, cement, painting
and fabrics manufacturers,...
• Consumer goods will also be grouped
into this type
– Quality or purity measures will be
much higher.
• Yogurts, ice creams, drinks,…
• Pharmaceutical and cleaning
products.

15. Process industry
• Four main steps
– Raw materials preparation
• Received in bulk and storage in
large warehouses or silos.
• Product mixing is carried out in
hoppers or in smaller drums.
– Treatment
• filter, dry, separate,...
– Finishing
• Restore some properties (Metals).
• Superficial treatments.
– Polishing or painting.
– Bottling or packaging
• Bottling or packing lines.

16. Assembly companies
• Companies that exclusively assemble
final products.
– Cars, televisions, microwaves.
• Their components are purchased
from external companies.
• Some processing operations are also
carried out internal to the factory.
– They are not profitable to
subcontract.
• Sheet cutting.
• Welding.
• Plastic injection molding.
• Painting.

17. Manufacturing companies
• Companies that manufacture
component parts do not belong to
any of the previous groups
– Forges
– Plastic injection machines
– Presses
– CNC machines.
• Factory layout depends on the
product type and volume to be
manufactured
– Later this will be analyzed in more
detail

18. Layout types
• There are numerous classifications of industry according
to their layout.
• We will use four basic layout groupings or classifications.
– The grouping is primarily the result of the material flow in
the production plant
• Fixed position layout
• Process layout
• Product layout
• Cellular or combination layout

19. Fixed position layout
• The product does not move
throughout the production process,
the needed resources do.
– Ships, buildings, trains,…
– Products with short or immediate
needs
• Milling center, presses,...
• Historically this layout was also used
for custom car production

20. Process layout
• Machines are grouped into
departments or stations according to
the operation that they perform.
– Presses -> pressing department
– Lathes -> lathes department
• Used in companies that manufacture
by orders.
– Specialty parts or components.
• A small job shop that makes
unique dies or fixtures
– Products that are made in very small
batches

21. Process layout. Advantages
• The flexibility of products (almost
any part that fits within the
volumetric boundaries of the
machines) is possible.
• An in depth understanding of a
specific process can be obtained.
• Some tooling and fixtures can be
shared.

22. Process layout. Disadvantages
• The spaghetti flow is difficult to
manage and control.
• There is usually a lot of inventory
in front of each machine.
• Set up is usually expensive and
time consuming.
• Material handling times are large.
• It is difficult to automate these
types of systems.

23. Product layout
• Machines are grouped according to
the product manufacturing sequence.
• These layouts are called
manufacturing or assembly lines.
– High volume component parts are
normally produced using a product
layout.
• Assembly companies normally use
this type of layout, especially in the
automotive sector.

24. Product layout
• The layout change carried out by
Henry Ford drastically reduced the
car production lead time.
– Some companies are able to
manufacture an automobile every 40
seconds.

25. Product layout. Advantages
• Large batches can be produced
inexpensively
• Material handling is minimal
• In-process materials are minimized
• It is easy to control these systems
• Automation is more achievable and
justifiable

26. Product layout. Disadvantages
• They are inflexible, in that only
one or very few products can be
produced on them.
• Set-up time for these systems is
very large.
• Duplicate tooling is required to
replace worn tooling so that
maintenance can be minimized.

27. Cellular or combination layouts
• Some companies can not be
classified exclusively by one of the
previous layout types.
• Large product manufacturing
industries (airplanes or presses)
have opted for modularization.
– Different modules are produced in
different lines and assembled as
subsets.

28. Cellular or combination layouts
• Dismantling sections and creating
manufacturing cells to
accommodate demand.
– Special screws manufactures.
– Cellular layout.
• Share the critical resource.
– High cost of the resources.
• Combination layout between
product and process layouts.

29. Cellular or combination layouts
• Common first phase and different
assembly lines to elaborate the
final product.
– Appliances manufactures.
• Plastic injection and presses
sections, combined with
assembly lines grouped by
product families.

30. Fixed positioned Process layout Product layout
Product
Difficult to move or with
small and specific
demand
Products diversified with
variable production
volume
Standard products with
high production volume
Material flow
The product does not
move
Manufacturing particular
path (standard routes do
not exist)
Unidirectional and the
same one for all products
Machinery
General machinery and
common to all products
Each machine
manufactures different
products
Specific machinery for
each operation
Labors
The task assignment
depends on the project
Specific skill in each
process
Repetitive tasks although
the rotation of the staff is
favored
Characteristic of the traditional layouts

31. Layout design methodology
• These next steps are applicable to most of the possible
layout problems, they are oriented mainly for a general
layout analysis.
• Step 1. Formulate the problem.
– Define what is the main objective of the study.
• Including a new machine?
• Modifying the existing building?
• Step 2. Analysis of the problem.
– Can be carried out in a systematic way.
• Richard Muther in his now classic book " Practical Plant
Layout " presented 8 factors to consider for facilities
layout.
– These factors will be described in the tools section.

32. Layout design methodology
• Step 3. Search for alternatives.
– The analysis of the 8 Muther’s factors enables engineers to
define the problem and properly align the solution to the
problem.
• It is important to take into account three practical
principles.
– First the whole and then the details.
– First the ideal solution and then the practical one.
– Brainstorming.

33. Layout design methodology
• Step 3. Search for alternatives.
– First the whole and then the details.
• Giving priority to the general area or total space shared
and then to each one of the specific areas.
• Layered planes are developed to characterize the
situation.

34. Layout design methodology
• Step 3. Search for alternatives.
– First the ideal solution and then the practical one.
• The ideal solution is difficult to reach.
– The good solutions can be more easily developed.
• A more particle approach is more worthwhile so as not to
waste time and effort analyzing this problem in depth.

35. Layout design methodology
• Step 3. Search for alternatives.
– Brainstorming.
• The “creation of ideas” with not a single solution being
rejected.
• Consider all the ideas without criticizing them.
– Being critical at this point can hinder the creativity
process.
– It would not be the first time that, from a seemingly
crazy idea, brilliant solutions are obtained.
– It is also important to remember that factories have a third
poorly used dimension.
• The height or overhead space.

36. Layout design methodology
• Step 4. Choose the right solution.
– Choose the solution that fits best among the solutions that
have been proposed in the previous step.
• Each one of the solutions should be evaluated according
to a specific set of criteria.
– Ranking each alternative from 0 to 10 according to the
established criteria.
– Evaluate each alternative from an economical standpoint.
– The simplest solution (between those which have received
good ranking) will always be the best choice.

37. Layout design methodology
• Step 5. Specification of the solution.
– The accepted solution will need to be fully
developed.
– Take care of safety measures in order to
avoid possible future industrial accidents.
• Occupational Health and Safety
Administration (OHSA) regulations and
the Labor Risks Prevention Law.
– Itemize all details for the plan, budgets and
schedule for the implementation of the
solution.
– Demonstrate quantitatively that the outlined
solution will provide benefits when
compared to the current situation.

38. Layout design methodology
• Step 6. Design cycle.
– Includes planning for modifications that arise due to
problems that appear while adopting a solution.
• Budget deviations, problems in the plant installations.
– At the end of the design process, the plant should work
more efficiently.
– It is always worthwhile to check to see if the adopted
solution works as expected.

39. Tools for layout study. Muther’s 8 factors
• By analyzing the following 8 factors, it is possible to
determine the main layout restrictions and requirements.
– Choose the best layout from a set of proposed solutions.
• Muther’s 8 factors.
– Material factor.
– Machinery factor.
– Labor factor.
– Movement factor.
– Wait factor.
– Service factor.
– Building factor.
– Change factor.

40. Muther’s 8 factors. Material factor
• This factor does not cover the study of the materials
that are utilized to manufacture the product.
• The purpose of this factor is to become familiar with the
different production steps that are needed to
manufacture the article.
– Analyze how the material is transformed from raw material
to a final product.
– Should be studied without considering the relative location
of each process in the factory.
• This factor helps to understand the company technology
and to know the company range of products.

41. Muther’s 8 factors. Material factor
• The machine types and the existing
number of machines on the factory
floor.
– Their principle dimensions in case this
becomes a critical constraint.
• Analyze the operating conditions so as
to avoid putting incompatible
machines together.
– Vibrations, temperature, etc.
• A heavy sheet metal press and a
precision coordinate measurement
machine are not very compatible.

42. • The staff related with the production department should
be counted.
– Covering machine operators to division heads.
– Material handling and maintenance operator input is
important.
• It is recommended to use worker-machine diagrams (a tool
that will be explained in a subsequent chapter).
– Discovery of the operations that the worker carries out on
the machine and the relative disposition of the elements in
the working area to simplify the worker tasks.
Muther’s 8 factors. Labor factor

43. Muther’s 8 factors. Movement factor
• Analyzes the materials flow between working centers.
– This flow does not add value to the product.
• As much handling as possible should be eliminated.
– Completely eliminating movement is an Utopian.
• There are mainly two tools to analyze the movement
between machines.
– The flow process chart.
– Transfer matrix.

44. • Flow process chart.
– Represents, in a graphic way, the
path and the actions carried out
on the product.
• Five standard symbols are
used.
• It is possible to combine two
or more of these actions.
– Circle -> Operation.
– Arrow -> Transport.
– Reversed triangle -> storage.
– Letter D -> a wait or delay.
– Square -> Inspection.
Muther’s 8 factors. Movement factor

45. • Flow process chart.
– Using these symbols as tools, movement improvements can
be envisaged and advantages quantified.
Muther’s 8 factors. Movement factor
Number Time (min) Distance (m) Workers
Operation 3 80 - 4
Transport 5 13 102 5
Inspection - - - -
Storage 3 2 - 2
11 95 102 11
Number Time (min) Distance (m) Workers
Operation 4 140 10 5
Transport 7 20 167 7
Inspection - - - -
Storage 3 482 - 2
14 642 177 14
Product 1
Product 2
TOTAL
TOTAL

46. • Transfer matrix
– A matrix representation of the work flow
• Shows the fraction of works that flows from a section to
all the others including the RM and FP warehouses.
– Considers the total amount of products that enter in a work
center
• The fraction moving to other work centers is calculated.
– This is distributed fractionally between the other sections.
Muther’s 8 factors. Movement factor
A
M1 M2 M3 M4 M5 Sal.
Ent. 0,7 0,2 0,1
D M1 0,5 0,3 0,1 0,1
E M2 0,7 0,2 0,1
S M3 0,6 0,2 0,2
D M4 0,6 0,4
E M5 1
A
M1 M2 M3 M4 M5 Sal.
Ent. 0,3 0,2 0,1 0,4
D M1 0,3 0,1 0,4 0,2
E M2 0,7 0,3
S M3 0,5 0,1 0,1 0,3
D M4 0,2 0,2 0,6
E M5 0,1 0,1 0,1 0,6 0,1

47. • Transfer matrix.
– Shows the volume of different products that flows between
working centers.
• It does not indicate how heavy they are, or the size of the
products.
• It is possible to use the same matrix concept but with a
differrent perspective.
– Factors such as the transferred weight or the number of
routes executed.
– These matrixes will help to make the decision of the relative
location of the departments in the factory plant
Muther’s 8 factors. Movement factor

48. Muther’s 8 factors. Wait factor
• This factor covers the study of the three main
warehouses
– Raw materials, work-in-process and final product.
• This factor objective is to determine the required space
by each one of the warehouses.
• Due to the magnitude of the warehouse study, a specific
layout project must be outlined.
• Because the warehouse layout is closely related with its
management (planning and control), it will not be
studied in this book.

49. Muther’s 8 factors. Service factor
• Analyze two different characteristics.
– The study of environmental workspace conditions
• Brightness, noises, smells, minimum working space.
– Decide what the acceptable parameters are with respect
the OHSA regulations and the Labor Risks Prevention Law.
– The working conditions are analyzed, but concerning the
plant service staff.
• These services are mainly, quality, logistics and
maintenance.
• Minimum maneuver space for the forklift trucks or other
special equipment used.

50. Muther’s 8 factors. Building and change factors
• Building factor.
– Analyzes the actual useful surface of the building.
• The plant shape, the columns, the window situation for
ventilation, and areas of possible extension.
• The surface area covered by gantry cranes limits the
number of layout alternatives.
• Change factor.
– The proposed layout will not be valid forever.
– The factor intends to observe, from a critical point of view,
the adopted solution.
• The application of this factor is without a doubt the
most difficult part of the study.
• Ask for future company plans.

51. Summary
This chapter has demonstrated how material flow can
significantly be improved by means of layout analysis. In
this kind of improvement projects, the study of the
current situation allows to identify constraints that
reduce the number of possible alternatives to be
considered. The proposed improvements will reduce the
material flow, allowing the company to raise the one-
piece-flow proposed by the Lean Manufacturing
philosophy.