1 Allocating Resources to the Project Expediting a Project Fast-Tracking a Project Resource Loading Allocating Scare Resources

2 Introduction Projects Compete With One Another for Resources –resources that are not consumed –resources that are consumed Goal of Resource Allocation is to Optimise Use of Limited Supply Requires making trade-offs –time constrained –resource constrained

3 EXPEDITING A PROJECT The Critical Path Method Probabilistic Activity Durations Fast-Tracking a Project

4 The Critical Path Method Normal Duration Estimates Normal Costs Crash Duration Estimates Crash Costs Crash Cost Per Day

5 Probabilistic Activity Durations Three time estimates made for both normal resource loading and crash resource loading Variance of normal activity may be different than variance of crash time

6 Fast-Tracking a Project Used Primarily in Construction Industry Building phase started before design and planning phases completed (Scottish Parliament) Particularly appropriate when large proportion of work is routine

7 Resource Loading Amount of specific resources that are scheduled for use on specific activities or projects at specific times. Usually a list or table.

8 Use of Software Begin with Pert/CPM Schedule Activities examined period by period and resource by resource In cases where demand for resource exceeds supply, tasks considered one by one and resources assigned to these tasks based on priority rules

9 Some Priority Rules As soon as possible As late as possible Shortest task duration first Minimum slack first Most critical followers Most successor Most resources first

10 Resource Loading/Leveling and Uncertainty What about –Workers getting sick? –Task not ready when worker is ready? –Change orders?

11 Pseudo activities Used to link several project together Have duration but do not require any resources This approach allows a set of projects to be dealt with as though it were a single project –use of MSP’s resource loading and leveling charts and tables

12 Bottle Necks Identify the constraint Exploit the constraint Subordinate everything else Elevate the constraint Go back to step 1

13 Goldratt’s Critical Chain What is it? Tackles the inherent uncertainty in managing projects Systems approach

14 Goldratt’s Critical Chain Similar issues that trouble people about working on projects regardless of type of project –unrealistic due dates –too many changes –resources and data not available –unrealistic budget These issues/problems related to need to make trade-offs To what extent are these problems caused by human decisions and practices?

15 Observations Average Completion Times Implications of Assuming Known Activity Times Worker Time Estimates Impact of Inflated Time Estimates Student Syndrome

16 Common Chain of Events Underestimate time needed to complete project Project team members inflate time estimates Work fills available time Safety time misused Misused safety time results in missed deadlines

17 Common Chain of Events concluded Poor multitasking increases task durations Uneven demand on resources also results due to poor multitasking More projects undertaken to ensure all resources fully utilized More projects further increases poor multi tasking

18 Reversing the Cycle Reduce number of projects assigned to each individual Schedule start of new projects based on availability of bottleneck resources Reduce amount of safety time added to individual tasks and then add some fraction back as project buffer –activity durations set so that there is a high probability the task will not be finished on time

19 The Critical Chain Longest chain of consecutively dependent events –considers both precedence relationships and resource dependencies Project Buffer Feeding Buffer

20 Critical Chain Rules 1. Projects should not be started ASAP 2. Tasks and resources should not be precisely scheduled during planning 3. Adding explicit buffers into projects makes them run faster

21 Buffer Management Taking the appropriate action No action needs to be taken, consumption of the buffer is expected Identify the tasks consuming the buffer, develop a recovery plan Implement recovery plan Use information on task performance for future improvement activities

22 Why not start projects ASAP? All three projects started ASAP Constant resource shuffling Priorities not synchronised All projects are delayed Start dates are staggered Resources stay focused Tighter synchronisation All projects finish faster More projects can be done

23 Why not schedule precisely? Schedules set in planning Uncertainties are unavoidable Wanting to be reliable, people add safeties into estimates Safeties get wasted in execution Schedules set in Execution Estimates are used only to plan projects Task schedules determined in execution, when tasks are closer to being started

24 How safety or contingency time is wasted Task dependency – Gains are wasted and delays are passed on Student Syndrome / Cherry Picking – Starting work is delayed Parkinson’s Law – “Work expands to fill the time available” Multi Tasking – A resource has to divide its time between two or more tasks

25 Benefits PROJECTS: coming in on-time completing within budget completing without cutting scope reduced project lead-times Improved efficiency

26 A resource allocation example

27 Often estimates of the time taken are quite inaccurate

28 Plan with Resource Allocation

29 Revised Plan with Resource Allocation

30 Plan with Levelled Resources and Warm Toast