Process design
Source: Joe Schwarz, www.joyrides.com
Process design
Process design
Operations
strategy
Supply network design
Layout
and flow
Process
technology
Design
Job
design
Product/service
design
Operations
management
Improvement
Planning and
control
1
Nature and purpose of the design activity
Products, services and the processes which
produce them all have to be designed
Decisions taken during the design of a product or
service will have an impact on the decisions
taken during the design of the process which
produces those products or services, and vice
versa
Design of products / services and design of processes
are interrelated and should be treated together
Designing the
product or service
Products and services
should be designed in
such a way that they
can be created
effectively
Designing the
process
Product / service
design has an
impact on the
process design and
vice versa
Processes should be
designed so they can
create all products
and services which
the operation is likely
to introduce
2
Design of
the Product
Design of
the Process
In manufacturing operations
overlapping the activities of
product and process design
is beneficial
Process mapping symbols
derived from ‘Scientific
Management’
Design of
the Service
Design of
the Process
In most service operations
the overlap between service
and process design is
implicit in the nature of
service
Process mapping symbols
derived from Systems Analysis
Operation (an activity that
directly adds value)
Beginning or end of the
process
Inspection (a check of
some sort)
Activity
Transport (a movement of
something)
Input or output from the
process
Delay (a wait, e.g. for materials)
Direction of flow
Storage (deliberate storage,
as opposed to a delay)
Decision (exercising discretion)
3
Designing processes
There are different ‘process types’
Process types are defined by the volume and
variety of ‘items’ they process
Process types go by different names
depending on whether they produce products or
services
Process
tasks
Process
flow
Diverse/
complex
Intermittent
High
Manufacturing process types
Project
Variety
Jobbing
Batch
Mass
Continuous
Continuous
Low
Repeated/
divided
Low
Volume
High
4
Project processes
One-off, complex, large-scale ‘products’ with
high work content
Specially made, every one ‘customized’
Defined start and finish: time, quality and cost
objectives
Many different skills have to be coordinated
A project process with a small part of the process map
that would describe the whole process
5
Jobbing processes
Very small quantities: ‘one-offs’, or only a few
required
Specially made: high variety, low repetition,
‘strangers’, every one ‘customized’
Skill requirements are usually very broad
Skilled jobber, or team, completes whole
product
Preparing photolithography materials on a jobbing basis
with a typical process map
6
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
A batch process in a kitchen together with an
illustrative process map
7
Mass (line) processes
Higher volumes than batch
Standard, repeat products (‘runners’)
Low and/or narrow skills
No set-ups, or almost instantaneous ones
A mass process – a packing process
8
Continuous processes
Extremely high volumes and low variety:
often single product
Standard, repeat products (‘runners’)
Highly capital-intensive and automated
Few changeovers required
Difficult and expensive to start and stop the
process
Part of a continuous process and a typical
process map
9
Diverse/
complex
Intermittent
Professional
service
Service shop
Variety
Process
tasks
High
Service process types
Process
flow
Repeated/
divided
Continuous
Low
Mass service
Low
Volume
High
A professional service –
Consultants planning how best to help their client
10
A service shop – This health club offers some variety
within a standard set of facilities and processes
A mass service – This call centre can handle
a very high volume of customer enquiries because it
standardizes its process
Source: Royal Bank of Scotland Group
11
Deviating from the ‘natural’ diagonal on the product–process
matrix has consequences for cost and flexibility
Manufacturing
operations
process types
Service
operations
process types
Volume
Variety
None
Project
Jobbing
Less process
flexibility than
is needed so
high cost
Batch
More
process
flexibility
than is
needed so
high cost
Professional
service
Service
shop
Mass
Continuous
Mass
service
None
The ‘natural’ line of fit of process to
volume/variety characteristics
Deviating from the ‘natural’ diagonal on the product–process
matrix has consequences for cost and flexibility
Volume
Variety
None
Old
process
Old
process,
new
product
New
process,
new
product
None
12
Flow (layout), technology and job design are all influenced
by process positioning
Flow
Technology
Volume
Jobs
Variety
Unorganized
Little /
general
Varied / high
discretion
None
Custom
furniture
maker
Machine
tool maker
Automobile
factory
Predictable
Specialist
Routine / low
discretion
Petrochemical
refinery
None
Flow (layout), technology and job design are all influenced
by process positioning
Flow
Technology
Volume
Jobs
Variety
Unorganized
Little /
general
Varied / high
discretion
None
Investment
banking
Customer
service
branch
Bank call
centre
Predictable
Routine / low
Specialist
discretion
None
Credit card
processing
13
Process mapping symbols
derived from Systems Analysis
Process mapping symbols
derived from ‘Scientific
Management’
Operation (an activity
that directly adds value)
Beginning or end of the
process
Inspection (a check of
some sort)
Activity
Input or output from the
process
Transport (a movement
of something)
Delay (a wait, e.g. for materials)
Direction of flow
Storage (deliberate storage,
as opposed to a delay)
Decision (exercising discretion)
Customized sandwich – old process
Raw
materials
Assembly
Stored
sandwiches
Standard sandwich process
Move to
outlets
Stored
sandwiches
Sell
Take
payment
Customer
request
14
Customized sandwich – old process
Raw
materials
Assembly
Take
payment
Customer
request
The operation of making and
selling customized sandwiches
Prepare
Sandwich
materials and
customers
Bread and
base filling
Assemble whole
sandwich
Assemble as
required
Take
payment
Customers
‘assembled’ to
sandwiches
Outline process of making and
selling customized sandwiches
Use standard
‘base’?
No
Yes
Fillings
Customer request
Assemble from
standard ‘base’
Detailed process of
assembling customized
sandwiches
Stored
‘bases’
15
Customized sandwich – new process
Assemble whole
sandwich
Assembly of
‘sandwich
bases’
Use standard
‘base’?
Take
payment
No
Fillings
Yes
Bread and
base filling
Customer request
Assemble from
standard ‘base’
Stored ‘bases’
Flow process charts for processing expense reports
at Intel before and after improving the process
1
2
3
4
5
6
Description of activity
Report arrives
1
Description of activity
Report arrives
Check expenses report
Stamp and date report
2
3
4
Check expenses report
Attach payment voucher
Send cash to receipt desk
Wait for processing
5
Wait for processing
6
Check advance payment
7
8 Send to accounts receivable
9
Wait for processing
10
Check employee record
11
Send to account payable
Attach payment voucher
12
13
14
15
16
17
18
19
20
21
22
23
7
8
9
Stamp and date report
Wait for batching
Collect retorts into batch
Batch to audit desk
Wait for processing
Check reports and vouchers
Reports to batch control
10
11
Batch control number
Copy of reports to filing
12
Reports filed
13
14 Payment voucher to keying
Log report
Check against rules
Wait for batching
Collect retorts into batch
15
Confirm payment
Totals
Batch to audit desk
Wait for processing
5 5 2 2 1
Batch of reports logged
Check payment voucher
Reports to batch control
Batch control number
Copy of reports to filing
24
Reports filed
25 Payment voucher to keying
26
Confirm payment
Totals
7 8 5 5 1
16
Little’s law (a really quite useful law)
Throughput (TH) = Work in process (WIP) × Cycle time (CT)
Cycle time
= 2 minutes
WIP = 10
Throughput time = ?
Throughput time = 10 × 2 minutes
= 20 minutes
Little’s law (a really quite useful law)
Throughput (TH) = Work in process (WIP) × Cycle time (CT)
500 exam scripts need to be marked in 5 days (working 7 hours a day).
It takes 1 hour to mark a script. How many markers are needed?
Throughput time = 5 days × 7 hours = 35 hours
35 hours = 500 scripts × Cycle time
Cycle time =
35 hours
500 scripts
= 0.07 hours
Number of markers = Work content = 1 hour = 14.29
Cycle time
0.07
17
Throughput efficiency
Throughput efficiency is the work content of whatever is
being processed as a percentage of its throughput time
Throughput efficiency =
Work content
Throughput time
× 100
Arrival
Arrival
30
9 5–15 105–15
20
10
Processing
Processing
frequency
frequency
time time
mins mins
mins
(demand)
(demand) mins
Utilization
Utilization
33.33
50
100
%%
%%
Utilization==<100
100%
X
QQ
Q==
Q
>=0infinity
00
Process
time
Average throughput
length of queue
(or inventory)
High
High utilization but
long throughput times
X
Low utilization but
short throughput times
X
Reduce process
variability
X
Low
0
20%
X
40%
X
60%
80%
X
100%
Capacity utilization
18
Decreasing
variability
Average number of units
waiting to be processed
Average number of units
waiting to be processed
The relationship between process utilization and number
of units waiting to be processed for variable arrival and
activity times
High utilization
but long waiting
time
Reduction in
process
variability
Y
0
10 20 30 40 50 60 70 80 90 100
Utilization
(a) Decreasing variability allows higher
utilization without long waiting times
0
X
Short waiting
time but low
utilization
Z
10 20 30 40 50 60 70 80 90 100
Utilization
(b) Managing process capacity
and/or variability
Key Terms Test
Throughput time
The time for a unit to move through a process.
Utilization
The ratio of the actual output from a process or facility to its
design capacity.
Life cycle analysis
A technique that analyzes all the production inputs, the life
cycle use of a product and its final disposal in terms of
total energy used and wastes emitted.
19
Key Terms Test
Process types
Terms that are used to describe a particular general approach to
managing processes. In manufacturing these are generally
held to be project, jobbing, batch, mass and continuous
processes; in services they are held to be professional
services, service shops and mass services.
Project processes
Processes that deal with discrete, usually highly customized,
products.
Jobbing processes
Processes that deal with high variety and low volumes, although
there may be some repetition of flow and activities.
Key Terms Test
Batch processes
Processes that treat batches of products together, and where
each batch has its own process route.
Continuous processes
Processes that are high volume and low variety; usually products
made on continuous processes are produced in an endless
flow, such as petrochemicals or electricity.
Professional services
Service processes that are devoted to producing knowledgebased or advice-based services, usually involving high
customer contact and high customization. Examples include
management consultants, lawyers, architects, etc.
20
Key Terms Test
Service shops
Service processes that are positioned between professional
services and mass services, usually with medium levels of
volume and customization.
Mass services
Service processes that have a high number of transactions, often
involving limited customization, for example mass transportation
services, call centres, etc.
Product–process matrix
A model derived by Hayes and Wheelwright that demonstrates the
natural fit between volume and variety of products and services
produced by an operation on one hand, and the process type
used to produce products and services on the other.
Key Terms Test
Process mapping
Describing processes in terms of how the activities within the
process relate to each other (may also be called process
blueprinting or process analysis).
Process mapping symbols
The symbols that are used to classify different types of activity,
usually derived either from scientific management or from
information systems flowcharting.
High-level process mapping
An aggregated process map that shows broad activities rather
than detailed activities (sometimes called an outline process
map).
21
Key Terms Test
Work content
The total amount of work required to produce a unit of
output, usually measured in standard times.
Throughput time
The time for a unit to move through a process.
Cycle time
The average time between units of output emerging from a
process.
Key Terms Test
Work-in-process
The number of units within a process waiting to be
processed further (also called work-in-progress).
Little’s Law
The mathematical relationship between throughput time,
work-in-process and cycle time:
Throughput time = work-in-process × cycle time
22