Resource Allocation
Andrea Polini
Software Project Management
MSc in Computer Science
University of Camerino
A.Y. 2016/2017
Andrea Polini Resource Allocation SPM – A.Y. 2016/2017 1 / 11
Resource Allocation
Introducing resources in planning
Plans discussed so far somehow assumed that resources where
not limited and no constraints on their usage are considered
Resources
A resource is any item or person required for the execution of the
project
When considered in planning (resource allocation) they result in the
definition of a number of scheduling:
activity schedule
resource schedule
cost schedule
Andrea Polini Resource Allocation SPM – A.Y. 2016/2017 2 / 11
Resource Allocation
Introducing resources in planning
Plans discussed so far somehow assumed that resources where
not limited and no constraints on their usage are considered
Resources
A resource is any item or person required for the execution of the
project
When considered in planning (resource allocation) they result in the
definition of a number of scheduling:
activity schedule
resource schedule
cost schedule
Andrea Polini Resource Allocation SPM – A.Y. 2016/2017 2 / 11
Resource Allocation
Typical resources
Resources can refer to:
Labour to perform project activities - full assignment vs. partial
assignment to the project
Equipment to be used to permit the work of labour (desks,
workstations ...)
Materials to be consumed during the project
Space in particular if additional personnel units have to be
recruited
Services to be used during the project (e.g. confcall services)
Time
Money resource needed to retrieve other resources
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Resource Allocation
Resource requirements
To identify required resources we need to consider each single activity
in the plan and define which are the needed resources
Stage Activity Resource Days Quantity Notes
1 Project Manager 65 F/T
All Workstation 17 Check for OS licenses
2 Planning Senior Analyst 7 F/T
... ... ... ... ... ...
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Resource Allocation
Scheduling resources
After having identified the resources we use a bar chart to derive
timewise the real needs . . . we need to do it wisely
Week number
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
System specification
2 1 1 1 1 1
Design subsystem A
2 2 2 1 1 1 1 1
Design subsystem B
1 1 1 1 1 1 1
Design subsystem C
2 2 1 1 1 1 1 1 1 1
Implement A, B
2 2 1
Implement C
2 2 1
Test system
A A
B B A B B
C C B A C C
D D C B A A A D D
A E E D C B B B A E E E
B A F F E D C C C B F F F
0 0 0 0 0 2 1 6 6 5 4 3 3 3 2 5 5 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Week number
Andrea Polini Resource Allocation SPM – A.Y. 2016/2017 5 / 11
Resource Allocation
Scheduling resources
After having identified the resources we use a bar chart to derive
timewise the real needs . . . we need to do it wisely
Week number
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
System specification
2 1 1 1 1 1
Design subsystem A
2 2 2 1 1 1 1 1
Design subsystem B
1 1 1 1 1 1 1
Design subsystem C
2 2 1 1 1 1 1 1 1 1
Implement A, B
2 2 1
Implement C
2 2 1
Test system
A A A A
A A B B B A A A A A A B A
A B B C C C B B B B B B C B
B A C C D D D C C C C C C D C A
0 0 0 0 0 2 1 3 3 4 4 4 3 3 3 3 3 3 4 3 1 0 0 0 0 0 0 0 0 0 0 0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Week number
Andrea Polini Resource Allocation SPM – A.Y. 2016/2017 5 / 11
Resource Allocation
Optimisations
Finding the best allocation is difficult and time consuming
Reduce maximum number of resource usage
Reduce idle time for resources
Reduce context switch for resources
Possible optimisation strategies suggest to:
Move activities within their float
Split activities
Additional constraints are introduced if allocation has to be based on
individuals
Andrea Polini Resource Allocation SPM – A.Y. 2016/2017 6 / 11
Resource Allocation
Optimisations
Finding the best allocation is difficult and time consuming
Reduce maximum number of resource usage
Reduce idle time for resources
Reduce context switch for resources
Possible optimisation strategies suggest to:
Move activities within their float
Split activities
Additional constraints are introduced if allocation has to be based on
individuals
Andrea Polini Resource Allocation SPM – A.Y. 2016/2017 6 / 11
Resource Allocation
Allocating strategies
It is useful to prioritize activites so that resources can be allocated on competing
activites in some rational order
Rule of thumb
Priority must almost always be to allocate resources to critical path activities and then
to those activities that are most likely to affect others
General strategies
Total float priority: activities are ordered according to their total float, those with
the smallest total float having the highest priority. As scheduling proceeds,
activities will be delayed if resources are not available and the total float is
reduced accordingly
Ordered list priority: activities that can proceed at the same time are ordered
according to a set of simple criteria (e.g. Burman proposal):
shortest critical activity
critical activities
shortest non-critical activities
non-critical activity with least float
non-critical activity
Andrea Polini Resource Allocation SPM – A.Y. 2016/2017 7 / 11
Resource Allocation
Generation of new critical activities
Scheduling resources can create new critical paths:
delaying an activity using all the available float
resource allocation can transform an activity into critical as
consequence of resource release related to a critical activity
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Resource Allocation
Allocating individuals
Often individuals are not considered the same “as resources”. Skill
and experience are generally important factors considered in resource
allocation
Availability: check departmental work plan and act wisely
Criticality: more experienced on critical path
Risk: more experienced on more complex and risky activities
Training: junior staff on non critical activities permits to foresee
training activities
Andrea Polini Resource Allocation SPM – A.Y. 2016/2017 9 / 11
Resource Allocation
Cost schedules
After having allocated the resources to activities and having defined a
schedule it is possible to derive the cost schedule for the project on a
weekly or monthly bases:
Staff costs
Overheads
Usage charges
Scheduling decision affect cost so it can be the case that it need to be
revised to optimize cost factors
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Resource Allocation
Resources
Study material can be found here:
Bob Hughes and Mike Cotterell
Software Project Management, 5th Ed.
McGraw-Hill, 2009
Chapter 7 - Resource Allocation
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