power point presentations 10

Slack, Chambers and Johnston, Operations Management, 6th Edition,© Nigel Slack, Stuart Chambers, and Robert Johnston 201010.1

10.1

Chapter 10

The nature of planning and control

Pearson Education Ltd. Jules Selmes


10.2

Design

Planning and control

Operations strategy

Improvement

Capacity planning and control

Capacity planning and control

The operation supplies... delivered products and

services

The market requires… products and services delivered to requested

time, quantity and quality


10.3

In Chapter 10 – The nature of planning and control – Slack et al. identify the following key questions:

•What is planning and control?

•How do supply demand affect planning and control?

•What are the activities of planning and control?

Key operations questions


10.4

•Planning is a formalization of what is intended to happen at some time in the future.

•A plan does not guarantee that an event will actually happen, it is a statement of intention.

•Although plans are based on expectations, during their implementation things do not always happen as

expected.

•Control is the process of coping with any changes that affect the plan. It may also mean that an ‘intervention’ will need to be made in the operation to bring it back ‘on track’.

Planning and control


10.5

Planning is deciding

Control is

what activities should take place in the operationwhen they should take place

what resources should be allocated to them

understanding what is actually happening in the operation

deciding whether there is a significant deviation from what should be happening

(if there is deviation) changing resources in order to affect the operation’s activities.

Planning and control (Continued)


10.6

PLANNING

CONTROL

Significance of planning and controlTi

me

horiz

onH

ours

/day

sD

ays/

wee

ks/m

onth

sM

onth

s/ye

ars Long-term planning and control

Uses aggregated demand forecasts

Determines resources in aggregated form

Objectives set in largely financial terms

Medium-term planning and controlUses partially disaggregated demand forecasts

Determines resources and contingencies

Objectives set in both financial and operations terms

Short-term planning and controlUses totally disaggregated forecasts or actual demandMakes interventions to resources to correct deviations from plansAd hoc consideration of operations objectives.


10.7 Dependent and independent demand

Dependent demande.g. input tyre store in automobile plant

Demand for tyres is governed by the number of automobiles planned

to be made

For every automobile that are planned to be made, five tyres will be

needed


10.8 Dependent and independent demand (Continued)

Demand for tyres is largely governed by

random factors.

ACE TYRES

Demand for tyres is governed by the type of car arriving, the fluctuations in the number of cars arriving and how

many tyres need replacing.

Independent demande.g. tyre-fitting service


10.9 P : D ratios

DP

Produce to stock

DP

Part produce to order

DP

Resource to order

Customer orders

Deliver to customer

Allow time for delivery

Produce product/service

Allow time for creation

Obtain resources

Allow time for resourcing

DP

Produce to order


10.10 P : D ratios (Continued)

Resource to order

Make to stock

Make to order

Dependent demand

Independent demand

Each product or service (large) compared with total capacity of the operation

Each product or service (small) compared with total capacity of the operation


10.11

Scheduling Loading

SequencingMonitoring and control

When to do things?

In what order to do

things?

How much to do?

Are activities going to plan?

The activities of planning and control


10.12

Quality losses Slow

running equipment

Equipment ‘idling’ ‘Breakdown’

failure

Set-up and changeovers

Not worked (unplanned)

Valuable operating time

Maximum available time

Loading – The reduction of time available for ‘valuableoperating time’

Not worked (planned)


10.13

Finite and infinite loading of jobs on three work centres A, B and C. Finite loading limits the loading on each centre to their capacities, even if it means that jobs will be late. Infinite loading allows the loading on each centre to exceed their capacities to ensure that jobs will not be late.

12

34

56

0

Work centre Work centreA B C A B C

Finite loading Infinite loading

Weeks

Finite and infinite loading


10.14

In Accident and Emergency departments, patients arrive at random. Medical staff must rapidly devise a schedule. Patients with serious illness need urgent attention. Less urgent cases will have to wait. Routine non-urgent cases will have the lowest priority of all.

The hospital triage system


10.15 Triage in the police


10.16

Process stage

Week 12

Week 13

Week 14

Week 15

Week 16

Week 17

Week 18

Job A Job B Job C Job D Job E

Job A Job BJob Y Job X

Job A Job BJob Z Job XJob Y

Job A Job BJob X Job C

Gantt chart showing the schedule for jobs at eachprocess stage

Initial spec

Pre-coding

Coding

Compact. check

Final test

Job A Job BJob W Job C Job D


10.17

JOB Mon 5

Tue6

Wed 7 Thur 8

Fri 9

Mon 12

Tue 13

Table

Shelves

Kitchen units

Bed

Actual progressTime now

V

V

Gantt chart showing the schedule for individualjobs over time

Scheduled activity time


10.18

JOB Mon 5

Tue6

Wed 7 Thur 8

Fri 9

Mon 12

Tue 13

Wood preparation

Assembly

Finishing

Paint

Scheduled activity time Actual progress

T

B

B T

S K

S S S

K

KTS

B T

Non-productive timeV

V

Time now

Gantt chart by activity


10.19 Pull and push philosophies of planning and control

Push control

Work centre

Work centre

Work centre

Work centre

Instruction on what to make and where to

send it

DEMAND

FORECAST

OR

CENTRAL OPERATIONS, PLANNING AND CONTROL SYSTEM


10.20

Pull control

Work centre DEMAND

Pull and push philosophies of planning and control (Continued)

Work centre

Work centre

Work centre

Request Request Request Request

Delivery Delivery Delivery Delivery


10.21 Pull and push philosophies of planning and control (Continued)


10.22

Shift allocation for the technical ‘hot line’ (a) on a daily basis (b) on a weekly basis

(a)Shift pattern (24-hour clock)

Peter

Jo

Walter

Jo

Marie Claire Jo

04:00 08:00 12:00 16:00 20:00

Peter X X X X O O X Marie X X X X X O O Claire X X X X O O X Walter O X X X X X O

Jo O X X X X X O

Mon Tue Wed Thu Fri Sat Sun

Number of staff required

3 5 5 5 3 2 2

(b)

X OFull day Day off

Shift allocation


10.23

Operation or processInput Output

Compare / replan

InterventionPlans

A simple model of control

Monitor


10.24 The drum, buffer, rope, concept

Stage or process

B

Stage or process

A

Stage or process

D

Stage or process

E

Buffer of inventory

Stage or process

C

Bottleneck drum sets the beat

Communication rope controls prior activities

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