Design. Improvement. Planning and control. Operations management. Process
design. Supply network design. Layout and flow. Process technology. Job design
.
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
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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)
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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
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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
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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
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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
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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
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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
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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
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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
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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’
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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
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Reports filed 25 Payment voucher to keying 26 Confirm payment Totals
7 8 5 5 1
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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
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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===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
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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.
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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.
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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).
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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
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