resource analysis 1
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Resource analysis 1. Project management ( seminar ). Introduction. Sometimes one or more resources (especially skilled workers) are equally or more important than time. According to priority, there are: time-limited and resource-limited - PowerPoint PPT PresentationTRANSCRIPT
Resource analysis 1
Project management(seminar)
Introduction• Sometimes one or more resources (especially
skilled workers) are equally or more important than time. According to priority, there are:– time-limited and – resource-limited
projects. Priority can change over time but it is not wise to have double priorities.
• Basic tools came from production engineering: loading (resource allocation)
Resources• Definition: anything that is scarce and required for any activity
in the project. Resources are constraints for the project.• Resources can be:
– Non-storable: has to be renewed for each periode.g. work
– Storable: depleted only by usage (remains available if not used)e.g. money
• The most common resource typology, the 4Ms:– Men– Machines– Money (cost)– Material – Other
Loading (resource allocation)• The assignment of work to an worker, machine
or unit (generally: to a workstation) in time.• A workstation can be:
– underloaded (load < capacity)– fully loaded (load = capacity)– overloaded (load > capacity)
• Fully loading is nearly impossible to reach except in flow production.
• Underloading is the most common, because it respects time. Overloading leads to be late.
Defining resources for projects• SOW• WBS• Task list
– Resource needs given in resource-hours (e.g. man-hour, machine-hour)
– Two forms of resource specification:• Rate-constant (can be changed to a constant
function/patter): constant usage rate defines the duration, too
• Total constant: to finish the activity
What to do with non-linear duration-resource functions?
• Use a computer• Focus on quasi-linear parts of the functions
Capacity
• Be realistic:– Usual efficiency– Estimated absenteeism, sickness, holidays– Existing commitments– Ancillary tasks and their resource needs– Any additional constraints (like methodology) and
limitations (like work contracts)
• Also calculate with the possibilities (cost, time, trade-offs) to increase capacity
Defining resources for projects 2• SOW• WBS• Task list• Logical connections (PNT)• Gantt chart and histogram• Levelling
Using the bar chart
• Set up and analyse the network– Assign the resource data to the activities
• Draw the Gantt chart– Aggregate each resource time period by time
period throughout the total project
• Cumulating (Summation or S Curve):• Use levelling the load for optimization
Network with single resource data
START (0)
0 00
0 00
0
e (1)
10 130
10 133
0
d (2)
2 73
5 105
3
c (3)
2 100
2 108
0
b (4)
0 55
5 105
5
a (1)
0 20
0 22
0
FINISH (0)
13 130
13 130
0
Aggregation with a bar chart(single resource, earliest start)
activity 1 2 3 4 5 6 7 8 9 10 11 12 13
a 1 1
b 4 4 4 4 4
c 3 3 3 3 3 3 3 3
d 2 2 2 2 2
e 1 1 1Res. aggr. 5 5 9 9 9 5 5 3 3 3 1 1 1Cum. res. 5 10 19 28 37 42 47 50 53 56 57 58 59
Resource units11 10
987654321
1 2 3 4 5 6 7 8 9 10 11 12 13
Time
Aggregation with a bar chart(single resource, latest start)
activity 1 2 3 4 5 6 7 8 9 10 11 12 13
a 1 1
b 4 4 4 4 4
c 3 3 3 3 3 3 3 3
d 2 2 2 2 2
e 1 1 1Res. aggr. 1 1 3 3 3 9 9 9 9 9 1 1 1Cum. res. 1 2 5 8 11 20 29 38 47 56 57 58 59
Resource units11 10
987654321
1 2 3 4 5 6 7 8 9 10 11 12 13
Time
The S Curve analysis
• The minimum slope level is the less ‘critical’ from the viewpoint of availability
S Curve of the example
0
10
20
30
40
50
60
70
1 2 3 4 5 6 7 8 9 10 11 12 13
ES
LS
smoothest
Scheduling with constraints
Three approaches:• Allocation: Activities are scheduled so that an
initially defined limit of resources or time is not exceeded.
• Levelling: A previously generated schedule must be given. Then it levels out the peaks and troughs without changing the TPT.
• Smoothing: A start time, a TPT and resource priorities.
Other possibilities
• Alternative resources• Alternative methods• Alternative sequences
(if there is no technical dependency)
Levelling the load• We must have a starting allocation of activities over
time and a resource constraint (previous example).Resource units
11
10
9
8
7
6
5
4
3
21
1 2 3 4 5 6 7 8 9 10 11 12 13
Time
• Trying to keep the original TPT unchanged means that critical activities should not be moved. Thus try to move activities with free float.
Resource units
11
10
9
8
7
6
5
4
3
21
1 2 3 4 5 6 7 8 9 10 11 12 13
Time
Solution• There are only 2 activities with free float: b & d• Which one to move and to where?
• Moving activity d 3 days in advance is eliminating the peak.
Resource units
11
10
9
8
7
654
3
21
1 2 3 4 5 6 7 8 9 10 11 12 13
Time
activity 1 2 3 4 5 6 7 8 9 10 11 12 13
a 1 1
b 4 4 4 4 4
c 3 3 3 3 3 3 3 3
d - - - 2 2 2 2 2
e 1 1 1Res. aggr. 5 5 7 7 7 5 5 5 5 5 1 1 1Cum. res. 5 10 17 24 31 36 41 46 51 56 57 58 59
0
10
20
30
40
50
60
70
1 2 3 4 5 6 7 8 9 10 11 12 13
ES
LS
smoothest
leveled
S Curve
Effect of levelling• New „activity”: waiting for the resource
(it is a lag, not a true activity)
START (0)
0 00
0 00
0
e (1)
10 130
10 133
0
d (2)
5 100
5 105
0
c (3)
2 100
2 108
0
b (4)
0 50
0 55
0
a (1)
0 20
0 22
0
FINISH (0)
13 130
13 130
0
• Changes: new precedence relationship, floats, late start and finish times
Reading
• Lockyer – Gordon (2005): Chapter 17
Thanks for your attention