The Process Flow Spectrum
 Spectrum Overview
 Intermittent Flow
Operations
 Continuous Flow
Operations
 Repetitive Flow
Operations
 Selection Criteria
Applied Management Science for Decision Making, 1e © 2012 Pearson Prentice-Hall, Inc.
Philip A. Vaccaro , PhD
The Process Spectrum
RAW MATERIALS
TO FINISHED GOODS
PRE-MADE PARTS ASSEMBLED
INTO FINISHED GOODS
RAW MATERIALS
TO FINISHED GOODS
Intermittent
Flow
Operations
Worker
Paced
Line
Flow
Continuous
Flow
Operations
( Job Shop )
Batch
Flow
Machine
Paced
Line Flow
ALL MANUFACTURING AND SERVICE OPERATIONS ARE
ENCOMPASSED BY THE PROCESS SPECTRUM
(Mass Production)
Layout Definitions
The placement of:
The spatial or physical
arrangement of:
 people
 equipment
 materials
within an organization
 machines
 offices and desks
 service centers
 inventories
within factories, warehouses, banks, offices,
stores, hospitals, etc.
Process Flow Structures Affect
 Layout of the facility
 Human and material
resources
 Technology decisions
 Work Methods
 Productivity
 Firm’s strategy for
competitive advantage
 Costs
Intermittent Flow Operations
 Called job shop in
everyday parlance.
 Can only occur within
process layouts.
Their products move very slowly
through the system due to material
shortages, long set-up times, worker
absenteeism, quality control
problems, technical difficulties,
and so on.
Process Layout Schematic
( INTERMITTENT FLOW OPERATIONS )
PRODUCT FINISH
Cutting
Center
Sanding
Center
Final
Inspect
Center
Drilling
Center
Assembly
Center
Painting
Center
WAIT LINE
EXIT
PRODUCT START
PRODUCT MOVES FROM CENTER TO CENTER , ENCOUNTERING STOP-AND-GO TRAFFIC FROM START TO FINISH
Characteristics
PROCESS LAYOUT
WORK FLOWS NOT STANDARDIZED
ONE OR MORE UNITS OF A PARTICULAR BATCH OF PRODUCT MAY NEED TO BE
RE-ROUTED THROUGH THE JOB SHOP DUE TO A MACHINE BREAKDOWN, OR SENT
BACK TO THE SAME WORK CENTER TWICE DUE TO QUALITY PROBLEMS OR
BREAKAGE.
LABOR – INTENSIVE OPERATIONS
HAND-CRAFTED OR HUMAN-DIRECTED MACHINE OPERATIONS ON THE GOODS
BEING PRODUCED.
HETEROGENEOUS PRODUCT MIX
A LARGE VARIETY OF DIVERSE PRODUCTS ARE CAPABLE OF BEING PRODUCED.
Characteristics
PROCESS LAYOUT
INTERRUPTED PRODUCT FLOW
PRODUCT FLOW IS BLOCKED OR DIVERTED BY MACHINE FAILURES,
MATERIAL SHORTAGES, CRITICAL WORKER ABSENCES, QUALITY
PROBLEMS, OR UNEXPECTED ADDITIONAL PROCESSING TIMES.
LOW PRODUCTION VOLUME
ONE, TWO, OR A FEW DOZEN UNITS OF THE SAME MAKE, MODEL,
MATERIALS, SIZE, AND COLOR ARE PRODUCED AT ONE TIME.
NO CLOSE MANAGEMENT SUPERVISION
SHOP FOREMAN TELLS WORKERS WHAT TO DO BUT NOT HOW TO DO IT.
S/HE SERVES AS A TECHNICAL RESOURCE ON CALL FOR WORKERS, KEEPS
THEM SUPPLIED WITH MATERIALS, AND ACTS AS A LIAISON BETWEEN THE
WORKERS AND THE CUSTOMERS.
Characteristics
PROCESS LAYOUT
GENERAL PURPOSE EQUIPMENT
EQUIPMENT THAT CAN FABRICATE MANY DIFFERENT TYPES OF PRODUCTS
BY MERELY CHANGING THE EQUIPMENT SETTINGS OR ATTACHMENTS.
THE EQUIPMENT CAN BE EMPLOYED IN A WIDE VARIETY OF ENVIRONMENTS,
WHICH IN TURN, MAKES IT RELATIVELY INEXPENSIVE TO PURCHASE.
EXAMPLE
A CARPENTRY JOB SHOP TABLE SAW CAN MAKE CUTS FOR BOOKCASES,
CHAIRS, DESKS, CABINETS, AND TABLES VIA A BLADE CHANGE OR MINOR
ADJUSTMENT.
Continuous Flow Operations
 Called mass production
in everyday parlance.
 Can only occur within
product layouts.
THEIR PRODUCTS MOVE QUICKLY
FROM STATION TO STATION ON A
SINGLE PRODUCTION LINE THAT
SELDOM STOPS.
Product Layout Schematic
( CONTINUOUS FLOW OPERATIONS )
Work Stations
1
2
3
4
INPUTS
LABOR
MATERIALS
LIQUIDS
Work-in-Process Units
Finished Units
Assembly Line or Pipeline
Characteristics
PRODUCT LAYOUT
PRODUCT MADE-TO-STOCK
IT PRODUCES PRODUCTS THAT ARE DESTINED TO GO TO A WAREHOUSE
FOR SUBSEQUENT DISTRIBUTION, OR A RETAILER FOR ROUTINE MERCHANDISE
REPLENISHMENT.
UNINTERRUPTED PRODUCT FLOW
PRODUCTION IS HALTED ONLY BY SCHEDULED MAINTENANCE, ACCIDENTS,
STRIKES, DELIVERY DELAYS, OR NATURAL DISASTER. MANY PRODUCTION
PLANTS OPERATE 24 HOURS A DAY, 7 DAYS A WEEK.
Characteristics
PRODUCT LAYOUT
HOMOGENEOUS PRODUCT MIX
A SINGLE BASIC PRODUCT WITH MINOR VARIATIONS SUCH AS COLOR,
OPTION PACKAGES, TRIM, SIZE, AND SO ON.
CAPITAL – INTENSIVE OPERATIONS
PRODUCTION THAT RELIES PRIMARILY ON MACHINES, ROBOTS, AND
COMPUTERS, WITH NOMINAL OR NO HUMAN INTERVENTION.
Characteristics
PRODUCT LAYOUT
DEDICATED OR SPECIAL-PURPOSE EQUIPMENT
EQUIPMENT DESIGNED FOR ONE SPECIFIC TASK, AND FREQUENTLY,
INDUSTRY-UNIQUE. IT IS EXPENSIVE BECAUSE IT IS PRODUCED IN
SMALL LOTS AND USUALLY POSITIONED AT MANY POINTS ALONG
THE ASSEMBLY LINE,
EXAMPLE
SPOT-WELD ROBOTS IN AN AUTOMOBILE PLANT ARE UNIQUE TO
THAT INDUSTRY AND POSITIONED EVERY FEW HUNDRED FEET
ALONG A ONE-MILE ASSEMBLY LINE. PRICES START AT OVER A
HALF-MILLION DOLLARS!
Repetitive Flow Operations
encompass
Intermittent
Flow
( Job Shop )
Batch
Flow
Worker
Paced
Line
Flow
Machine
Paced
Line Flow
Continuous
Flow
( Mass Production )
A TRANSITION ZONE BETWEEN INTERMITTENT & CONTINUOUS FLOW OPERATIONS
Characteristics
REPETITIVE FLOW OPERATIONS
 Assembly of pre-made parts
from independent vendors
or sister divisions
 Semi-skilled labor is utilized
 Limited product menu is
produced ( 6 to 12 )
 All products “made” on the
same assembly line.
( at different times, of course )
 Products share similar parts,
technology, and processing
steps
 Just-in-time systems are used
to control the inventory.
PROCESS FLOWS
Let’s take a closer look!
Process Structure Characteristics
 Flow

Labor Content
 Flexibility

Labor Skill

Production
Volume
 Number of Products
 Capital Investment
 Variable Cost
EACH OF THESE
CHANGES AS
WE MOVE
ACROSS
THE
SPECTRUM
Process Structure Characteristics
Intermittent
Flow
Operations
Continuous
Flow
Operations
FLOW
FROM A LARGE NUMBER OF
POSSIBLE SEQUENCES OF
ACTIVITIES TO ONLY ONE
POSSIBLE SEQUENCE
PRODUCT NUMBER
FROM THE CAPABILITY OF
PRODUCING MANY
DIFFERENT PRODUCTS TO
PRODUCING ONLY 1 PRODUCT
VARIABLE COST
VOLUME
FROM A HIGH UNIT COST
TO A LOW UNIT COST
FROM A QUANTITY OF ONE
TO LARGE-SCALE MASS
PRODUCTION
Process Structure Characteristics
Intermittent
Flow
Operations
Continuous
Flow
Operations
LABOR SKILL / CONTENT
FLEXIBILITY
FROM HIGH SKILL AND
CONTENT TO LOW
SKILL AND CONTENT
PROCESS PERFORMANCE
AND COST ARE
INDEPENDENT OF
CHANGES IN OUTPUT
CAPITAL INVESTMENT
FROM USING LOW COST
GENERAL PURPOSE
EQUIPMENT TO HIGH COST
DEDICATED EQUIPMENT
Project Architecture
• FLOW – no flow
• VARIABLE COST – very
high
• FLEXIBILITY – very high
• LABOR CONTENT &
SKILL – very high
• PRODUCTS – unique
• VOLUME – one unit
• CAPITAL INVESTMENT
– very low
Project Architecture
Comments
 Resources are brought to the project site
as needed.
 Technically, a project is not a process flow
structure, since there is no flow of product.
 However, it is useful to think of a project as
one extreme of the process continuum.
Project Architecture
Financial
Implications
 Relatively low fixed costs.
 Relatively high direct labor costs.
 Relatively high direct materials costs.
 Low materials handling costs.
Job Shop Architecture
• FLOW – jumbled flow
• VARIABLE COST – high
• FLEXIBILITY – high
• LABOR CONTENT &
SKILL – high
• PRODUCTS – many
• VOLUME – low
• CAPITAL
INVESTMENT – low
Jumbled Flow
( NO DOMINANT FLOWS THROUGH THE SYSTEM )
Center
1
Center
2
Center
4
Center
3
Center
6
Center
5
Product A
Product B
Product C
Product D
Job Shop Architecture
Financial
Implications
 Relatively low fixed costs.
 Relatively high direct labor costs.
 Relatively high direct materials costs.
 High material handling costs.
Batch Process Architecture
• FLOW – disconnected, with • VARIABLE COST –
some dominant flows
moderate
• FLEXIBILITY – moderate
• LABOR CONTENT
& SKILL – moderate
• PRODUCTS – several
• VOLUME – moderate
• CAPITAL
INVESTMENT – moderate
Jumbled Flow
( WITH SOME DOMINANT FLOWS )
Center
1
Center
2
Center
4
Center
3
Center
6
Center
5
Product A
Product B
Product C
Product D
Potential
Islands
Of
Automation
Jumbled Flow
( WITH SOME DOMINANT FLOWS )
Center
1
Center
2
Center
4
Center
3
Center
6
Center
5
Product A
Product B
Product C
Product D
Disconnected Flow
One flow only but the work centers are separated from one another
in TIME and SPACE
Center
1
1,000 ft
Center
2
800 ft
Center
3
1st Floor
or
Building No. 1
2 miles
2nd Floor
or
Building No. 2
Center
4
600 ft
Center
5
900 ft
Center
6
Batch Process Architecture
Comments
 Products are produced in “batches”
( several dozen units at a time ) .
 More frequently produced products
begin to create dominant flows between
certain work centers.
 The sequence of operations subsequently
tends to form one or more “production
lines”.
 The sequence(s) of operations, while
“in-line”, is/are still disconnected.
Assembly Line Architecture
WORKER + MACHINE PACED
• FLOW – connected line • VARIABLE COST – low
• FLEXIBILITY – low
• LABOR CONTENT &
SKILL – low
• PRODUCTS – a few
• VOLUME – high
• CAPITAL INVESTMENT
– high
Connected Flow
( All work centers equidistant from one another and synchronized )
3 Minute Time Interval Between Centers
Center
1
Center
2
Center
3
Center
4
Center
5
20 Feet of Distance Between Centers
Center
6
Assembly Line Architecture
Comments
 Like a “batch” process, it processes
work in a fixed sequence.
 However, it connects and paces the
work via a moving production line.
 There is now only one production line!
Continuous Flow Architecture
• FLOW – continuous
• FLEXIBILITY – very low
• PRODUCTS – one
• CAPITAL INVESTMENT
– very high
• VARIABLE COST - very
low
• LABOR CONTENT AND
SKILL – very low, but
with skilled overseers
• VOLUME – very high
Continuous Flow
Very little or no time interval between work stations
Very little or no physical separation between work stations
Work
Station
1
Work
Station
2
Work
Station
3
Work
Station
4
Processing Steps
- heating
- cooling
- drying
- mixing
Resource inputs
- liquids
- materials
Work-in-Process
Finished Product
VERY HIGH SPEED PRODUCTION RATE
( process or actual pipeline )
Continuous Flow Architecture
Comments
 Has a fixed pace and sequence of
operations.
 A single product is processed in a
continuous flow, rather than in
discrete steps.
 Production output is measured in
weight or volume.
Continuous Flow Architecture
Financial
Implications
 Relatively high fixed costs.
 Relatively low direct labor costs.
 Relatively low direct materials
costs.
The Process Flow Spectrum
Project
Job
Shop
Batch
Process
Assembly
Line
Continuous
Flow
Flow
None
Jumbled
Disconnected
& Dominant
Connected
Continuous
Flexibility
Very High
High
Moderate
Low
Very Low
Number of
Products
Unique
Many
Several
Few
One
Capital
Investment
Very Low
Low
Moderate
High
Very High
Variable Cost
Very High
High
Moderate
Low
Very Low
Labor Content
Very High
High
Moderate
Low
Very Low
Labor Skill
Very High
High
Moderate
Low
Very Low
Volume
One Unit
Low
Moderate
High
Very High
Process Selection Criteria
 Product variety
 Product volume
 Local economics
 Stage in product
life cycle
 The firm’s business
strategy + marketing
plans
 A tradeoff between
fixed + variable cost
 The amount of capital
that the firm is able
or willing to invest
Marketing Implications
PROCESS CONTINUUM
A job shop allows a firm
to sell its capabilities
A continuous process
flow allows a firm to
emphasize the product itself
A job shop helps a firm
follow a differentiation
strategy
A continuous process flow
helps a firm follow
a low-cost strategy
Economic Implications
PROCESS CONTINUUM
 Labor
A BREAK-EVEN ANALYSIS MAY BE
PERFORMED TO ASSIST IN THE
PROCESS SELECTION
A BREAK-EVEN CHART RELATES
COST TO LEVELS OF FORECASTED
DEMAND
 Energy
 Equipment
 Transportation
Product Life Cycle Implications
PROCESS CONTINUUM
BIRTH
MATURITY
DECLINE
A JOB SHOP MAY
BE THE MOST
APPROPRIATE
IN ORDER TO
FILL EARLY
DEMAND AND
ADJUST TO
DESIGN CHANGES
HIGH PRODUCTION
VOLUMES MAY
JUSTIFY AN
ASSEMBLY LINE
A BATCH PROCESS
MAY BE MORE
APPROPRIATE AS
PRODUCT VOLUME
FALLS AND A
VARIETY OF SPARE
PARTS IS REQUIRED
Traditional Process Layout
PRODUCTS CONTINUALLY TRAVEL BETWEEN WORK CENTERS
Lathe Center
Drilling Center
Cutting Center
Inspection Center
Work Cell Layout
GROUP TECHNOLOGY
- All jobs take the same route through the shop
- Machine setups for all jobs are accomplished by merely changing the
software menu
- Interchangeable product parts or parts that merely have to be reduced
or increased in size, also make the work cell layout possible
Work Cell Layout
REQUIREMENTS
 Quick set-up times between
jobs
 Reprogrammable robots and
other equipment
 Production of products
sharing similar process
requirements, parts,
materials, shapes,
and handling
requirements
Work Cell Layout Management
STORM DOOR & WINDOW FACTORY
Shop makes windows of
all sizes, metals, wood, vinyl,
glass, and colors with the
minimum setup times between
each order
Major
Setup Time
Between
Window
&
Door
Runs
Shop makes storm doors of
all sizes, metals, wood, vinyl,
glass, and colors with the
minimum setup times between
each order
Work Cell Layout Management
Setup Time and Setup Cost
Setup time is the time to prepare a machine
or process for manufacturing an order.
It includes time and labor to clean or
change tools, molds, or settings.
Setup cost is highly correlated with setup
time, and also includes the cost of lost
productivity, scrappage, and rework.
Work Cell Layout Management
MAJOR SETUP
(CHANGE BETWEEN PRODUCT GROUPS)
WINDOWS
DOORS
O
R
D
E
R
O
R
D
E
R
O
R
D
E
R
O
R
D
E
R
O
R
D
E
R
O
R
D
E
R
1
2
3
1
2
3
Work Cell Layout Management
MINOR SETUP
(CHANGE WITHIN A PRODUCT GROUP)
WINDOWS
WINDOWS
O
R
D
E
R
O
R
D
E
R
2
1
The Process Spectrum
RAW MATERIALS
TO FINISHED GOODS
PRE-MADE PARTS ASSEMBLED
INTO FINISHED GOODS
RAW MATERIALS
TO FINISHED GOODS
Intermittent
Flow
Operations
Worker
Paced
Line
Flow
Continuous
Flow
Operations
( Job Shop )
Batch
Flow
Machine
Paced
Line Flow
ALL MANUFACTURING AND SERVICE OPERATIONS ARE
ENCOMPASSED BY THE PROCESS SPECTRUM
(Mass Production)
The Process Flow Spectrum
Project
Job
Shop
Batch
Process
Assembly
Line
Continuous
Flow
Flow
None
Jumbled
Disconnected
& Dominant
Connected
Continuous
Flexibility
Very High
High
Moderate
Low
Very Low
Number of
Products
Unique
Many
Several
Few
One
Capital
Investment
Very Low
Low
Moderate
High
Very High
Variable Cost
Very High
High
Moderate
Low
Very Low
Labor Content
Very High
High
Moderate
Low
Very Low
Labor Skill
Very High
High
Moderate
Low
Very Low
Volume
One Unit
Low
Moderate
High
Very High
Intermittent Flow Operations
MANUFACTURING
Job Shop
Batch Flow
 ORIGINAL ART WORK
 LIMITED EDITION ART














TOOL & DIE SHOP
CUSTOM JEWELRY
HEIRLOOM FURNITURE
YACHT
SUPER COMPUTER
DENTAL CROWNS
CUSTOM POOL
HEAVY MACHINERY
FINE JEWELRY
FINE FURNITURE
ROBOTICS
SUITS
AMBULANCES
TEXTBOOKS
Repetitive Flow Operations
MANUFACTURING
Worker-Paced
Line Flow
Machine-Paced
Line Flow
 CAMERA ASSEMBLY
 APPLIANCE ASSEMBLY
 COMPUTER ASSEMBLY
 AUTOMOBILE ENGINE
ASSEMBLY
 STANDARD OFFICE
FURNITURE
 COMMON HAND TOOLS
 TOY ASSEMBLY
 AUTOMOBILE ASSEMBLY
 NEWSPAPER
PUBLISHING
 BOTTLING PLANT
 UTENSILS
Continuous Flow Operations
MANUFACTURING
 OIL REFINERY








CHEMICAL REFINERY
PAPER MILL
CONCRETE PRODUCTION
LIGHT BULB PRODUCTION
GLASS PRODUCTION
NUT & BOLT PRODUCTION
STEEL MILL
ELECTRICITY GENERATION
Intermittent Flow Operations
SERVICE SECTOR
Job Shop
Batch Flow
 TUTORING
 SMALL CLASSES
PHYSICIAN’S OFFICE
LIMOUSINE SERVICE
CHARTER FLIGHTS
LAW FIRM
PRIVATE DINING
FACILITY
 INDIVIDUAL SELLING
 GENERAL HOSPITAL
 TAXI SERVICE
 LOCAL AIRLINE
 LAW CLINIC
 FINE DINING
RESTAURANT
 BOUTIQUE





Repetitive Flow Operations
SERVICE SECTOR
Worker-Paced
Line Flow
Machine-Paced
Line Flow
 LECTURE HALL TEACHING
 DISTANCE LEARNING
 HERNIA SURGERY CLINIC
 BUS SERVICE
 SUPERMARKET
 FAST FOOD RESTAURANT
 SCHEDULED AIR LINE
 CARWASH
 CINEMA MULTIPLEX
 LAUNDROMAT
 TANNING SALON
 AMUSEMENT RIDES
Continuous Flow Operations
SERVICE SECTOR
Continuous
Line Flow
 RADIO - TELEVISION
 TELEPHONE SERVICE
 UTILITIES
 ON-LINE SHOPPING
 POLICE PROTECTION
 FIRE PROTECTION
 NATIONAL DEFENSE
 EMERGENCY MEDICAL
RESPONSE
 CHECK CLEARING HOUSE
 AUTOMATED FLAT- MAIL
POSTAL FACILITY
Classifying Service System Processes
WE FOCUS ON…..
1. How much skill and knowledge the worker must
bring to the service.
2. The size of the potential customer service group.
3. The level of customer convenience.
The Process Spectrum
THE END
Applied Management Science for Decision Making, 1e © 2012 Pearson Prentice-Hall, Inc.
Philip A. Vaccaro , PhD