Design for Six-Sigma
in the School of Computing, Engineering and Physical Sciences
Types of operations
by Dr J. Whitty
1
Lessons structure
• The lessons will in general be subdivided
in to eight number of parts, viz.:
1)
2)
3)
4)
5)
6)
7)
8)
2
Statement of learning objectives
Points of orders
Introductory material (Modes of organization)
Concept introduction (Product life cycle
stages)
Development of related principles (Flow
processes)
Concrete principle examples via –
reinforcement examination type exercises
Summary and feedback
Formative assessment, via homework task
Learning objectives
• Principles of operational process
management apply to services and
manufacturing.
• compare jobbing, batch and flow process
approaches to work organisation
• see how these apply to work in services
and manufacturing
• Specifically, describe the usage of types of
operations in Nuclear decommissioning
• Answer Examination type questions
involving production processes
3
Examination Type Questions
1.
4
(5)
Carlton Press Ltd is a small publishing company
specialising in educational books. Draw a diagram
showing the typical stages of production and
distribution of one of its books.
Basic modes of organising work
How can operations/jobs be done?
•
•
•
•
•
Jobbing (jumbled flow)
Project
Batch (disconnected line flow)
Assembly line (connected line flow)
Continuous flow process
Advantages/disadvantages of each.
Most processes combine two or more.
Choice based on experience, organisation skills,
investment, practicality and economy
5
Product Life Cycle Stages
1. Low volume, low standardization, one of a
kind
2. Multiple products, low volume
3. Few major products, higher volume
4. High volume, high standardization,
commodity product
6
Class discussion
• Name the five types of production processes
present in modern day manufacturing
– Give an example of each used in a real manufacturing
company.
– Give an advantage and disadvantage of each of the
processes identified
– Name a management method of control of each of these
processes
7
Jobbing
• All tasks performed by the same person. One part
of the task is completed before the next starts.
• multi-skilled operatives required: all equipment,
manual abilities, artistic competence and
decision-making.
• A project with a “team” which combines to
complete the whole is a more complex jobbing
activity.
Class Exercise: Find on the internet two
companies which operate primarily a Jobbing
production regime
8
Jobbing
• Non-Repetitive, Customised production
enhances value > diminishes it. Several multi-skilled
people may produce the same product. Organisation
& control to ensure key product features at every
repetition. Quantities small & to customer spec.
• Equipment
Basic craft tools. Key equipment shared &
scheduled. Equip't waiting time - a key factor.
• Costing of products
labour + materials + overheads. ----> selling price .
Premium prices for uniqueness, workmanship &
materials quality.
9
Batch operation
The work done in batches with separate,
sequential operations.
Example 1
– collect your dirty washing as two loads (5 minutes)
– Put Batch A in the washing machine.
– When washed, dry batch A in tumble drier while batch
B is washed.
– When A is dry, B can be dried whilst A is ironed.
– B is then ironed
– 15 mins to wash batch, 12 mins to dry, 35 mins to iron
a batch
Example 2
– prepare and cook 235 breakfasts to be served on
Quantas flight QT567K to Melbourne
10
Flow Process
• Not all work done in batches.
• Commercial dish washing machines &
factory biscuit baking ovens
incorporate a feed conveyor belt. Dirty
plates or biscuits are washed or
baked in a smooth non-stop operation
(flow).
11
Line Flow
WS 1
WS
Task or work station
Product flow
12
WS 2
WS 3
Batch Production
Shop
•
•
•
•
Similar layouts + equipment to job shop.
Batch progress in stages.
Work done by one person or team at workstation then moves on
Separation of design, planning & scheduling
– Order received & work systematically defined &
organised. Drawings, tools, staffing
– main assemblies, subs & components etc.
– Ops for each part/assembly,
machines/workstations where work occurs + timing
of each step
• Materials supplied to workstation for the batch.
• WIP - When item 1 n process, the rest queue
13
Batch Flow
WS 2
WS 1
WS
WS 3
Task or work station
Product flows
14
WS 4
WS 5
Class Exercise:
Find on the
internet two
companies
which operate
primarily a batch
production.
Batch operations
information system
• systematic recording, storage, access & dissemination of
batch operations data: instructions, progress & work
changes
• Managers, industrial engineers, planners examine
efficiencies & update operational specifications
• Computers & database systems, documented procedures &
meticulous administrators
• Operators carry out the work - set ups, quality, JIT etc
15
Data collection and
Batch analysis
•
•
•
•
optimum batch sizes ? No “one right answer”.
hundreds of batches in progress - each with different status
production control records to track every batch.
high levels of “work in progress” (variety of work and batch
hold ups).
• data collection points and logging
• bar code scanning for up-to-the-minute analysis: delays,
bottlenecks, lost time, quality problems and costs.
16
Batch costs & resource
utilisation
• large, inflexible, expensive items of equipment?
• Large batch sizes reduce average set up costs/unit Objectives
–
–
–
–
reduce change-over times and set-up costs.
high utilisation of people and key equipment
insert new jobs with minimum interruption
Hit deadlines, improving work methods especially
for repeat jobs
– lowest cost operations with minimum down time,
high quality and customer service.
• Competitive aim = take smaller orders, give better prices,
quality and responsiveness.
• Flexibility: CAD, CAM/CNC, cell technology
17
Batch processing applies
to services also.
• data processing (payroll, trial balance runs, master file
updating) on corporate computers?
• lunch & sandwich making in a college cafeteria?
Hamburgers & chips in a fast-food restaurant?
• Flying eye-operation theatre?
• Today's patients at out-patients' clinic?
• processing of tax demands sent out to individuals?
• How are car repairs done in a garage?
• Baggage handling at an airport
• Preparing dinner for 2/3 people vs. a wedding buffet
for 150?
• assembly of TVs., PCs, cars, flat-pack furniture
18
Flow Production
• manufacturing or assembly process where work
done on a product in a steady, sequence as it
moves along a track.
• The track does not stop (no idle time).
• Operators, at work stations, perform tasks on the
product as it passes thru. the workstation.
• Line dedicated to one product . No “batch” as such.
• A flexible continuous flow line may be capable of
switching to a model or product variant.
19
Capacity and Demand
Variations
• Track speed determines through-put
capacity.
• Speed governed by slowest point on the
line - (bottleneck).
• Production planning to balance line
capacity with demand.
• +/-staffing levels, overtime, extra shift,
make for stock
20
Investments & costs - expensive
dedicated flow line
•
•
•
•
•
•
•
•
21
Downtime ---> no feed to down-stream clients.
Poor quality at a station continues down the line.
Rectifying faults at line end is expensive
Upstream servers need holding areas to keep going
Rapid response repair & planned maintenance systems
Manage supply to stations – MRP or Kanban/JIT
operations at stations benefit from work study
Control product changes & equipment
installation/maintenance - to avoid disruption
Flow Process Staffing and Skills
• Operators- skilled/trained only for tasks at
workstation?
• Simpler recruitment & training but routinised
and repetitive. Little operator discretion over
speed/sequence of work and methods.
• Technology determined - limited scope for
line worker interaction .
• Operators must be high focused + work
rhythm
• Alienation with routine, continuous,
pace????
22
Job re-design & group/cell
technology
• From late 60s - job flexibility & empowerment e.g.
Herzberg & Volvo
• team at a work statio n- a “cell” - manage own
activities, roles & methods
• multi-skilling, job rotation & QA by by team itself.
• re-engineer how technology is implemented.
– adapt technology to people - not viz.
– Form cells (workstations) where work can stop & operators
(team) can do a series of tasks
• “Team” emphasis - group problem-solving supported
by specialists & management when needed.
23
Project Flow
Task 2
Task 4
Start
End
Task 1
Task
Task or activity
Precedence relationship
24
Task 3
Group Discussion:
 Given these definitions in your buzz groups
agree on two criteria in order decide where
and when each of the processes should be
employed.
 Hence produce a pictorial process selection
chart, based on these criteria.
25
Group Discussion: Service
Analogues
 There are two service model analogues, these
being proposed by two different authors,
these being:
 The tri-process model (Greasley,2009*)
 The four process model (Lovelock, 1992)
 In your buzz groups discuss the expressions,
via the use of cogent examples

Professional service, Service shop and Mass service
 Hence describe three and four service model
analogues to those described in the lecture,
via defining the term Service factory, via the use of
a Variety/Volume chart.
26
*Secondary source!
Group Discussion: Service
Analogues
 There are two service analogues proposed are


The tri-process model (Greasley,2009*)
The four process model (Lovelock, 1992) includes a service facttory,
 The analogues are usually described ion terms of
specific layout-designs:
Mass
Batch
Jobbing
Project
Fixed
Position
Continuous
Process
Cell
Professional
Shop
27
Mass
Product
Short Answer
Examination Type Questions
1. What product is produced in Nuclear Decommissioning? (1)
2. What is meant by the term Deindustrialisation? (1)
3. State three principal types of operational processes employed
in nuclear decommissioning (3).
4. The disposal of nuclear waste can be viewed as a hybrid
business sector activity, give examples of this by completion of
the following table
Kind of business activity
Definition
Example
Primary
Secondary
Tertiary
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(5)
Summary
• Have we met our learning objectives, namely
Session Objectives
• compare jobbing, batch and flow process
approaches to work organisation
• see how these apply to work in services and
manufacturing
• Specifically, describe the usage of types of
operations in Nuclear decommissioning
• Answer Examination type questions involving
production processes
29
Homework:
Examination Essay Type Questions
5. Write an essay of 1000-1200 words describing how nuclear
decommissioning operates within three principal business
operational sectors, explaining the organisation of specific
operational processes used. With reference to front and back
office actives describe the possible the use of the so called
three-process and four-process models within the industry (35)
30