A
25
25
Project management
Activity 25.1 (page 466)
1 Verify the ESTs above by working through the diagram from left to right, taking the longest route, in days, to each node.
Node 1 2 3 4 5 6 7 8 EST 0 0 + 8 = 8 0 + 8 + 14 = 22 0 + 8 + 12 = 20 0 + 8 + 14 + 10 = 32 0 + 8 + 14 + 10 + 3 = 35 0 + 8 + 14 + 10 + 3 + 3 = 38 0 + 8 + 14 + 10 + 3 + 3 + 4 = 42
Activity 25.2 (page 467)
1 Verify all of the LFTs by your own calculation.
Node 8 7 6 5 4 3 2 1 LFT 42 42 – 4 = 38 42 – 4 – 3 = 35 42 – 4 – 3 – 3 = 32 42 – 4 – 3 – 14 = 21 42 – 4 – 3 – 3 – 10 = 22 42 – 4 – 3 – 3 – 10 – 14 = 8 42 – 4 – 3 – 3 – 10 – 14 – 8 = 0
Activity 25.3 (page 468)
1 Draw the network for Project X. [6]
A 4 B6 1 0 0 D 12 3F G 16 3 10 5 10 22 28 22 6 25 25 C 7 4 E9 11 13 H 3 7 28 2 4 4
A
2 Use the duration times to calculate the EST and LFT of each activity. [6]A B C D E F G H
EST 0 4 4 10 11 22 4 25
LFT 4 10 13 22 22 25 25 28
3 Identify the critical path. [2] ABDFH
4 Explain the importance of this critical path to the operations manager. [6] Th is identifi es the minimum time for completing the project.
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Critical activities must fi nish on time for the project to be completed on time.
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Critical activities have no total fl oat – they cannot be delayed without delaying
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the completion of the project.
Th e operations manager will know that s/he needs to carefully monitor the
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progress of critical activities to ensure that the project is not delayed. If any critical activity is delayed, the operations manger will seek to divert
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resources from non-critical activities to try and get critical activities back on track.
Activity 25.4
− answer provided on Student’s CD-ROM.Revision case study 1 (page 471): Jamaica Photos Ltd
1 Construct a CP network diagram for this project based on the following information: A is the start of the project
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B, C and D cannot start until A is complete
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E follows B, C and D
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F has no preceding activity
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F must be completed before I can commence
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G and H follow E•
I follows G and H.•
[6] A 2 C 2 1 0 2 0 2 2 E 3 G 3 H 2 D 2 3 6 4 6 9 14 9 5 12 12 F 8 B 4 I 2 6 14A
2 Identify the critical path by inserting all ESTs and LFTs. [4] Critical path = ABEGI3 Explainwhy this critical path must be supervised carefully. [4]
As critical activities have no total fl oat, it means that any delay in completing an activity will delay the completion of the project. In this case it would mean having a more prolonged adverse impact on production and, therefore, customer delivery times.
4 Calculate all free and total fl oats for the non-critical activities. [6] Free fl oat = EST (next activity) – duration – EST
Total Float = LFT – duration – EST
Activity Free fl oat Total fl oat
C 2 2
D 2 2
F 4 4
H 1 1
5 Analyse the usefulness of this technique to the project team, considering the possibility of delays occurring on any of the activities. [10]
Th e technique aids the project team to calculate the minimum time for
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switching production from one site to the other.
Identifying the project time will help minimise disruption to production and
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customers.
Th e analysis provides a clear target for the project team and a basis for awarding
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a bonus on completion of the closure.
If delays occur to critical activities, the analysis will help the project manager
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identify if there are resources that can be diverted to try and keep the project on time.
Knowledge of the LFT provides a useful control tool for the project manager.
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It identifi es when processing at Kingston should be suspended so as to ensure
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the project is completed in the minimum time. Th is indicates that as long as processing is suspended, by day 4 the project can be completed within 14 days. 6 To what extent will critical path analysis guarantee that this project will be
successfully completed? [14]
Th e analysis does not guarantee that the project will successfully be completed within 15 days. Th ere are a number of reasons why the analysis does not guarantee successful completion of the project; these include:
Th e timings are only estimates. Th is is a unique project and, therefore,
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managers cannot be sure exactly how long each element will take. For example, testing the new integrated processing system may take longer than two days because of unexpected diffi culties. Machinery could easily be damaged during its dismantling, transport or rebuilding.
A
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Th e accuracy of the estimates depends on the ability and knowledge of the managers planning the closure.External factors, over which the project team has no control, can aff ect the
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closure. For example, contractors used for transporting the machinery may prove to be unreliable.
However, it will aid the completion of the project with a minimum of disruption as it will ensure that the project has been planned and consideration given to which activities can be completed simultaneously. It will help identify when resources are needed and at what point activities need to occur. Further, by identifying critical activities, it will help project managers to focus on those activities that have no fl oat, to try and prevent any delay from occurring.
Revision case study 2 (page 472): Network diagram
1 Calculate all ESTs and LSTs for the network shown in the above fi gure. [6]
Node 1 2 3 4 5 6 7 8 9 10
EST 0 10 20 20 34 22 59 42 74 82 LST 0 52 48 20 62 64 59 70 74 82
2 Calculate the duration of the critical path. [2] Critical path = EHKL = 82 days
3 Calculate total fl oats on all of the non-critical activities. [6]
Activity Free fl oat Total fl oat
A 0 28 B 0 42 C 8 36 D 0 28 F 0 42 G 0 28 I 14 42 J 28 28
4 Explain the disadvantages to the operations manager of ordering goods needed for task D to arrive on: [4]
Day 25
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Th e EST for activity D is 20 days, so if goods arrive on day 25, the activity will be delayed. However, this will not delay the completion of the project because activity D has 28 days of fl oat. Th erefore, it may be argued that receiving goods on day 25 is much earlier than necessary. As the latest start time for activity D is 48 days, goods could be organised to arrive then.A
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Day 15 Th e EST for activity D is 20 days and, therefore, there is no benefi t in ordering the necessary goods to arrive so early as they cannot be used until day 20. Th is would mean that the business is paying for goods long before it needs to.Essay
1 a Explain why effi cient project management is important for a business operating in a competitive market. [10]
Project management involves using techniques such as CPA to ensure that a project is completed on time, on budget and to the required quality. In competitive markets, effi cient project management is important because:
Th e ability to win contracts may depend on being able to complete a project to a
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pre-set schedule, e.g. building contracts.
Th ere may be fi nancial penalties for late completion.
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If project management is ineffi cient, then the fi rm’s activities will be disrupted
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for longer than necessary.
Effi cient project management aids planning the use of resources and ensuring
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their effi cient utilisation.
b Evaluate the usefulness of critical path analysis to a construction business building a new sports complex to a completely new design. [15]
CPA is useful to the construction fi rm because:
It identifi es the time when diff erent resources are required on site, e.g. bricks,
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roofi ng materials etc.
It identifi es when labour is required, e.g. bricklayers, electricians etc. Th is helps
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prevent labour being idle or contractors arriving too early or too late. It identifi es the critical path. Th e site manager will be able to focus on the
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critical activities to ensure that they are not delayed.
It identifi es activities that can be completed at the same time.
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It identifi es the minimum time for completion of the sports complex. CPA
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works eff ectively with time-based management as it is a way of focusing upon how time can be minimised. If the customer wants the sports complex fi nished by a particular date, CPA will indicate whether this is possible.
As resources will be managed more effi ciently, the building costs will be
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reduced.
In complex projects, CPA is particularly useful as planning is critical to the
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effi cient execution of the project.
However, there are a number of weaknesses of CPA, including:
As the sports complex is a new design, the accuracy of the timing estimates will
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be subject to uncertainty.
Th e plans are drawn up in an offi ce and conditions on site might not be as
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expected, so delays may occur.
It is assumed that their own employees and their contractors can meet the
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A
Evaluation may consider:CPA is a planning tool and as such will aid the construction fi rm to manage its resources eff ectively. Th is will help costs to be minimised and profi ts will be increased for the fi rm; it will also contribute to providing customer satisfaction as it is more likely that the sports complex will be fi nished on time. CPA is widely used in the construction industry for the reasons outlined above. However, it is not uncommon for major projects to overrun on time and budget. A notable project on which there was a time-management problem was the building of the main stadium for the Olympic Games in Athens in 2004 − the building was only completed two months before the opening ceremony. However, even where circumstances change or estimates prove inaccurate, CPA is still a useful technique because it forces managers to plan and this will reduce delays and help control costs.
