9 estimation methods

Question 1

what are the 5 estimation methods?

Answer 1

1 global/ approximate 
2 factorial
3 labour-hours
4 unit rate 
5 operational

Question 2

What is the project data required for global method?

Answer 2

1 size
2 location
3 completion date

Question 3

What is the project data required for factorial method?

Answer 3

1 main items
2 location
3 completion date

Question 4

What is the project data required for labour-hour method?

Answer 4

1 quantities 
2 location
3 key dates 
4 simple method statement 
5 completion date

Question 5

What is the project data required for unit-rate method?

Answer 5

1 bill of quantities
2 location
3 completion date

Question 6

What is the project data required for operational method?

Answer 6

1 material quantities 
2 method statements 
3 programme
4 key dates 
5 completion date

Question 7

What is the cost data required for global method?

Answer 7

1 overall cost of similar projects
2 inflation indices
3 inflation forecasts

Question 8

What is the cost data required for factorial method?

Answer 8

1 factorial estimating system
2 quotes for main plant items
3 inflation forecasts
4 ancillary item factors

Question 9

What is the cost data required for labour-hours method?

Answer 9

1 hourly rates 
2 productivity 
3 overheads 
4 material cost 
5 hourly rate forecasts 
6 material cost forecasts
7 plant data

Question 10

What is the cost data required for unit-rate method?

Answer 10

1 historical unit rates for similar work
2 preliminaries
3 inflation indices
4 inflation forecasts

Question 11

What is the cost data required for operational method?

Answer 11

1 labour rates and productiveness 
2 plant cost and productiveness 
3 material costs 
4 overhead costs 
5 material costs forecasts
6 plant capital operating cost forecasts

Question 12

What are the issues associated with global estimating?

Answer 12

1 may not include all fees ie final account sums, D&E fees, finance costs, land
2 difficult to define capacity and trend may not be linear
3 may not be comparing like with like ie different land conditions, different standards of quality ie motorway to minor road
4 reliability of data source

Question 13

What are the issues associated with factorial estimating?

Answer 13

1 reliability of the factors - need to be built up by experience
2 changes to the design change the factors
3 reliability of the price of equipment
4 adjustment for inflation needed

Question 14

What are the issues associated with labour-hours estimating?

Answer 14

1 it assumes that most operations do not vary in their method for different projects
2 allowances are made for materials costs therefore as less applicable for projects where there is a high material element

Question 15

Where do the unit rates come from?

Answer 15

1 historical rates based on productivity rates for similar projects
2 rates based on data given in price books
3 rates built- up from an analysis of labour, plant and materials for each item and costed at current rates
4 taken from estimators personal manual

Question 16

What are the issues associated with unit-rates estimating?

Answer 16

1 There are hidden costs such as storage and facilities for workers that are not included
2 It assumes that materials can be unloaded as soon as they arrive, at the place they are needed
3 no account for how many staff members there are to do the task
4 there might be travel time needed during the activity
5 there might be similar materials that slow down the output rate
6 no account for plant idleness
7 assumes resources will always be available

Question 17

What are the advantages of the operational method?

Answer 17

1 accounts for idle time
2 allows for operations where there is significant uncertainties and risks, as it shows the basic sources of costs and not the cost derived from an output.
3 the programme helps identify sources and risks of delay
4 will eventually accumulate a library of operational data

Question 18

What influences the accuracy of a cost estimate?

Answer 18

1 The accurancy of the cost model
2 Accuracy of the data fed into it
3 number of items it contains

Question 19

What are the main disadvantages of the operation model?

Answer 19

1 It does not allow direct entry of overheads

2 it is time consuming

Question 20

Give an example of when a global estimation would be used?

Answer 20

a new school

Question 21

Give an example of when a factorial estimation would be used?

Answer 21

a chemical plant

Question 22

Give an example of when a labour-hours estimation would be used?

Answer 22

electrical installation

Question 23

Give an example of when a unit-rate estimation would be used?

Answer 23

road

Question 24

Give an example of when a operational estimation would be used?

Answer 24

pouring concrete