1. Project management (seminar)
Resource analysis
Project management
(seminar)

2. 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)

3. 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 period e.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

4. Loading (resource allocation)
The assignment of work to a worker, a machine or a 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.

5. 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/pattern): constant usage rate defines the duration, too
Total constant: to finish the activity

6. What to do with non-linear duration-resource functions?
Use a computer
Focus on quasi-linear parts of the functions

7. 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

8. Optimum seeking procedures
Constraints:
Resource-limited projects
Time-limited projects
Resource-limited AND time-limited projects (question of priority)
Methods:
Linear programming
Levelling
Allocation
Smoothing

9. Linear programming
Successful only for small networks (up to about 200 activities)
Need for precise data

10. Levelling (simplest technique)
Need for a previously produced starting schedule.
Attempts to level out peaks and valleys in resource requirements by rescheduling some activities.
Difficulty of interactions between activities.

11. Allocation (for resource limited cases)
Allocation of resources
‘Splitting’ an activity: stopping an activity, which is currently in progress, by the removal of its resources for use on an activity of higher priority.
Two procedures for allocation:
Serial: if only a few activities are able to be split
Parallel: if many activities are splitable; more complicated method that needs more time and data

12. Allocation when resources are limited: serial procedure
All activities in the project are ranked using constant priority rule, BEFORE scheduling takes place. The most frequently used rule: ascending order of the LSTs with a tiebreaker of the ascending order of total floats (a kind of ‘urgency’).
Activities are scheduled in the above order at the earliest possible point in time consistent with the availability of resources and the precedence requirements.
Step-by-step process:
Draw the network diagram for the logical connections
Compute the activity times and total floats
Plot a Gantt or time-scaled network in tandem with a resource-histogram

13. Allocation when resources are limited: parallel procedure
Only those activities which are able to start, by virtue of preceding activities being complete, are ranked in priority order using a constant rule at any scheduling period.
Activities are considered sequentially (sub-lists). Unscheduled activities are retained and ranked in the next period with new activities.

14. Resource limits are: XX: 5; YY: 6; ZZ: 7
START A 4 B 1 C D 3 G F 5 E H K J 6 I 8 L
FINISH
Resource limits are: XX: 5; YY: 6; ZZ: 7
We are scheduling per time-periods. A period is defined by preceding activities being complete (a period ends when this changes).
At the 1st day 3 tasks can be started.
They must be ranked 1st by LST and 2nd by float.
Only a limited resource use is allowed per day, thus some activities must be postponed to the next day due to this limit.
The same process (dependency check, ranking, limit check) is repeated for the 2nd calendar time when and so on…
A Gantt-chart or of a time-scaled network must be created in tandem with the calculation.

15. The time-limited case Balancing the S-curve with milestones:
Forcing early activities to start sooner

16. Smoothing (time limited case)
The aim is to produce a feasible schedule within the time constraints & provide as smooth a resource requirement profile as possible.
Informational needs of smoothing:
Start time and timeframe (TPT or deadline)
Priority order of the resources required
Prioritising activities and selecting them in order for scheduling (critical activities have supreme priority).
Finding the best place for the activity (placing).
Repeat the process with the next activity.

17. Prioritising activities
Considerables:
Resource type(s) and importance (resource priority)
Total work content (resource units per time multiplied with the duration for all resources used on the activity)
Available float
Formula if no initial scheduling exists:
(Total work content) / (Float remaining)
In descending order (greatest first).

18. Placing
The best position is the one that gives the lowest usage increase in the time span of the activity.
Two ways of finding this position:
Visual
Sum of squares:
Calculate the sum of squared resource needs of each period within the questionable time frame (between the ES and LF time of the given activity) for every possible positioning
Choose the position with the lowest value

19. Exercises

20. Defining resources for projects
SOW
WBS
Task list
Logical connections (PNT)
Gantt chart and histogram
Levelling

21. 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

22. Network with single resource data2 10 8
a (1) 2
START (0)
e (1) 10 13 3
FINISH (0) 13
d (2) 2 7 3 5 10
b (4) 5 10

23. Aggregation with a bar chart (single resource, earliest start)
activity 1 2 3 4 5 6 7 8 9 10 11 12 13 a b c d e
Res. aggr.
Cum. res. 19 28 37 42 47 50 53 56 57 58 59
Resource units 11 10 9 8 7 6 5 4 3 2 1 12 13
Time

24. Aggregation with a bar chart (single resource, latest start)
activity 1 2 3 4 5 6 7 8 9 10 11 12 13 a b c d e
Res. aggr.
Cum. res. 20 29 38 47 56 57 58 59
Resource units 11 10 9 8 7 6 5 4 3 2 1 12 13
Time

25. The S Curve analysis
The minimum slope level is the less ‘critical’ from the viewpoint of availability

26. S Curve of the example

27. 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 are required.

28. Other possibilities Alternative resources Alternative methods
Alternative sequences (if there is no technical dependency)

29. 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 2 1 12 13
Time
Resource units 11 10 9 8 7 6 5 4 3 2 1 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.

30. 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 6 5 4 3 2 1 12 13
Time

31. activity 1 2 3 4 5 6 7 8 9 10 11 12 13 a b c d - e
Res. aggr.
Cum. res. 17 24 31 36 41 46 51 56 57 58 59

32. S Curve

33. Effect of levelling
New „activity”: waiting for the resource (it is a lag, not a true activity)
c (3) 2 10 8
a (1) 2
START (0)
e (1) 10 13 3
FINISH (0) 13
d (2) 5 10
b (4) 5
Changes: new precedence relationship, floats, late start and finish times

34. Network with single resource data2 10 8
a (2) 2
START (0)
e (1) 10 13 3
FINISH (0) 13
d (2) 2 7 3 5 10
b (4) 5 10
Resource limit: 5

35. Network with multiple resource data
c (3A) 2 10 8
a (2A) 2
e (3B) 10 13 3
START (0)
FINISH (0) 13
d (2B) 2 7 3 5 10
b (4B) 5 10
f (3A) 5 8 10 13 3
Resource limits: 5A, 5B

36. Reading
Lockyer – Gordon (2005): Chapter 17 & 18

37. Thanks for your attention