6th Edition PMBOK® Guide–Process 6.5 Develop Schedule: Tools and Techniques (3)

In this series of posts, I am discussing the tools and techniques used in the process of developing the schedule.   The overall technique is called schedule network analysis, and it begins with the critical path method, which I discussed in the last post.   It got its own post because it not only is important in its own right, but the questions on the PMP exam  asking you to calculate the critical path of a given network are some of the most time-consuming on the exam, and I wanted to give some guidance on how to answer them.

Here I discuss some of the other techniques used in the process.  Resource Optimization

There are two techniques, resource leveling and resource smoothing.   These sound similar, so let’s understand the difference.

  • Resource leveling is when certain critical resources for an activity are only available for a certain quantity per day.   If you have an activity that is scheduled for Monday, and it requires people to work overtime, your boss may prefer that you take some of the work and shift it to the next day so that people are only working 8 hours a day at maximum on the project.    Resource leveling might also occur if one of the resources is splitting his or her time between more than one project.   Say Resource A is working on two projects at once, yours and some one project manager’s project; then his or her maximum amount of time that he or she can spend on your project is now only 4 hours a day at maximum.    If that resource is critical for your project (i.e., can’t be replaced with someone else), and that person is scheduled to work on your project on Monday for 8 hours, then you might have to shift 4 hours of that work to the next day.   You can see how resource leveling might add extra days to the project work to accommodate work rules in terms of maximum amount of hours allowed per day.
  • Resource smoothing–once resource leveling is done, a further shift in resources can be done through resource smoothing.   Let’s say that Resource A is working on an activity for 8 hours during the week.   If the activity has to get done on Friday, there’s no reason why all 8 hours of the work has to get done on Monday.   The work can be spread out to 4 hours on Monday and Tuesday, so that Resource A can have time to work on other projects and/or operational work.    This kind of delay within the free float of four days (since it doesn’t have to completed until Friday) to accommodate the work preferences of resources is what resource smoothing accomplishes.  Data Analysis

These are analyses of scenarios that represent the effects on the schedule of various project risks.

  • What-if scenario analysis–by asking the question “how would the schedule be affected if scenario X happens”, you can help create a response plan to address the impact of such a situation if it were to occur.
  • Simulation–this is the “what-if scenario analysis” on steroids, as it models the combined effects of individual project risks.   The most common simulation technique is Monte Carlo analysis which calculates the possible effects on the schedule if certain project risks were to occur.   The result is a probability distribution that says for example, that there is a 90% probability of achieving a project deadline of a certain date. Leads and Lags

Lags are delays after a predecessor activity before a successor activity can take place.   Leads are advances in the successor activity so that it can start taking place even before the predecessor activity has completely finished.  Schedule Compression

If you complete your schedule network analysis, and it shows a completion date for the project which is unacceptable, you may have to attempt to shorten the project completion by one of the following two schedule compression techniques.   Each of them has a potential negative affect on one of the other constraints in the project, so you need to be careful when using them.

  • Crashing–adding more resources to get the job done more quickly.   This of course has a negative impact on the constraint of cost.   A typical crashing technique is approving overtime work, or paying to bring in additional resources.
  • Fast tracking–taking two activities which are done in series one after the other and moving up one of them so that it is done in parallel with the other at least during part of its duration.   This has a potential negative impact in terms of risk to quality because it may cause confusion and require some of the work to be redone.  Project Management Information System (PMIS)

The software you use for scheduling is a tool rather than a technique.  Microsoft Project is an example of this. Agile Release Planning

In an agile methodology, the project is broken down into releases (from 3 to 6 months out typically), and then each release has a set of iterations that are planned to take place every 2 or 4 weeks.   Each iteration will have a plan to schedule feature development, where the features are prioritized by user stories (the agile equivalent of deliverables), and the user stories are broken down into tasks (the agile equivalent of activities).   See p. 216 in the PMBOK Guide for Figure 6-20 which demonstrates this process graphically.

The next post covers the outputs of the Develop Schedule process.



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