Project Management Institute

Sleepless in Seattle? Avoid the scheduling nightmares

Introduction

So you are not sleeping well these days? Your project is getting you down? Tylenol PM™ is not the answer. Let's look at your schedule development efforts to see how some small improvements can give you a better nights rest.

Experience has shown that people do not do well on the scheduling development questions of the PMP® Exam. One of the reasons is people think schedule development is “just” throwing the activities into Microsoft Project™. We need to examine the process PMI® uses for schedule development and identify ways to improve the practice within the profession.

Schedule Development Process

The PMBOK® Guide that “schedule development means determining start and finish dates for project activities. If the start and finish dates are not realistic, then the project is unlikely to be finished as scheduled. The schedule development process must often be iterated (along with the processes that provide inputs, especially duration estimating and cost estimating) prior to determination of the project schedule.” By definition, we need to develop a realistic schedule to have a chance at project success. We should understand how to develop this realistic schedule with a review of the process inputs, tools and techniques and outputs. With this understanding we can then look for ways to improve our practices.

Process Inputs

There are six major inputs to the process; resource pool description, calendars, constraints, assumptions, risk management plan, and activity attributes.

The resource pool will provide a look into the availability of critical resources and overbooked skills. Knowledge of these items will allow us to schedule activities requiring these resources to the available times.

Calendars will provide feedback to us on limitations to the use of resources such as company holidays, proposed down times, and other pertinent information.

Constraints include imposed dates and key events or major milestones. The two most frequently used constraints are “start no earlier than” and “finish no later than.” These will limit the options available to us as we try to match resources with activities. An example would be getting a product to market or avoiding the rainy season. The milestone dates may have been set during initiation and have become “expected” dates rather than requests by management. The dates may also reflect dependencies on other projects or external activities.

Assumptions provide us with a way to move forward without having complete information. The drawback is the assumptions may be incorrect or inconsistent with the final project direction. As these assumptions are fleshed out, they may significantly impact our options for schedule development.

The risk management plan defines a process for managing areas that will require added monitoring and possible rework to reduce risk to an acceptable level.

Activity attributes, such as where the activity will be performed, the skill levels required, and the level of detail required will all impact how activities are scheduled.

These inputs provide a basic understanding of how to effectively use the tools and techniques to map the network diagram to a calendar.

Process Tools and Techniques

Tools and techniques that are used for schedule development include mathematical analysis (PERT, GERT, and CPM), duration compression (crashing and fast-tracking), simulation (Monte Carlo analysis and what-if analysis), resource leveling heuristics, and project management software. Each of these tools or techniques helps us solve a piece of the puzzle.

Mathematical analysis helps the project manager to determine which activities are on the critical path or near critical paths and require more intense monitoring than the rest. It also indicates which activities will need to be shortened to reduce overall project duration. They also provide a range of dates when the activity might occur—between the early start and the late finish. Using PERT and GERT will take into account some of the risks associated with each activity.

Inevitably, there will be requests or need to shorten the schedule. PMI recommends that we use duration compression to accomplish this task. There are two common ways to get the needed schedule compression—fast-tracking and crashing.

Fast-tracking involves rearranging activities laid out in series in our network diagram and scheduling them in parallel. This will not work for all sets of activities and we must be careful that the added risk of doing the work in parallel does not cause a delay greater than the time saved. Normally the activities are done in series for a reason; past experience has shown that problems happen when we do them in parallel. For example, in house construction having the plumbers and the electricians working at the same time creates more conflict and rework than if they are allowed to have access independently. Examining the level of rework and conflict and comparing it to the anticipated benefits will allow us to make an informed decision.

Crashing involves adding resources to an activity to complete it faster. This normally is associated with an increase in project cost. Added resources need to be acquired from somewhere; our choices range from the resource pool of available people, to consultants, to moving project assigned resources from noncritical activities (those with sufficient float) to the critical activities. This will require negotiation with functional managers as well as interface with the contracting office.

Not widely used in the field, especially on small or noncomplex projects, simulation can provide us with extremely useful information. When used, it could provide a greater certainty of meeting the schedule by providing specific probabilities for events as well as allowing “what-if” analysis of the schedule. “What-if” analysis can help find the least risky and most opportune path to follow. The required effort to set up the simulation and running the analysis is not always worth the results that can often be intuitively seen on smaller less complex projects.

Sometimes activities are laid out so that there are peaks and valleys in resource usage. To help make use of resources in a balanced way, we use resource leveling. As we level resources we take activities that may be scheduled for one week of intense work and spread the work out over three weeks of routine level of effort. This will do the opposite of schedule compression in that the activities and possibly the project overall will take longer to complete. This is used when the schedule is flexible but there are constraints on available resources. It is also used when management wants to have continuous use of resources and avoid the peaks and valleys.

To be able to look at many options quickly as we negotiate to finalize the schedule, project management software is needed. It allows automated recalculation of the schedule for each option or combination examined. Without the software, we would have many hours of work to examine the options and probably would not pursue it any further.

These tools and techniques, used effectively will allow us to pull together the vast number of competing priorities into a cohesive schedule.

Process Outputs

The output of schedule development is a completed, fully approved project schedule. This is the baseline from which we will measure project progress. Getting to a fully approved schedule is only a dream for many project managers. We need to identify practices that will make it a smoother process and easier to achieve.

Tricks for Creation

To return to that peaceful easy feeling and relieve the insomnia, we need to address issues with our schedules. There are many tricks that can help us create a more accurate and robust schedule. Let's examine these tricks.

Many times we are required to create a schedule based on imposed milestones. If we want to stay up nights, we should meet those dates by cutting all activity duration estimates by 10%. This is a quick correction but will only lead to a false sense of security. Remember, your estimates are supposed to be realistic estimates. Cutting activity durations assumes the estimates are NOT realistic. Don't use broad cuts; use a surgical approach. Using your network diagram, first to determine the critical path. Use the Gantt view to review the project milestone and completion dates. Compare these dates to the imposed dates and get an idea of how much you need to adjust the schedule. Then focus your efforts on adjusting the activities on the critical path (duration compression) to meet your constrained dates. If needed, also examine reducing scope of the project to remove activities or reallocate resources to meet the dates.

Do loud noises keep waking you? Those are the stakeholders screaming for attention. All of your stakeholders need to know what is happening on the project. Have you identified them and do you understand their needs? If not, you will have trouble getting their buy-in and support as you execute the project. Communicate with them early and often.

Are you dreaming of being a rat in the maze? Maybe you don't understand your network well enough. Sometimes when we translate the relationships to our project management software, we make mistakes. Understand your network diagram and the relationships that are displayed. With a good understanding of the network, you will be better able to work the network. You will be able to know where the “wiggle room” is in your project and where you might be able to borrow resources for crashing. You also will be able to better identify good candidates for fast-tracking.

Another hazard to a good nights sleep is not allowing the team to review the schedule. Most project managers do a good job of putting together a schedule using their project management software. They create a magnificent work of art and they distribute it to the team, expecting rave reviews. However, they often find that the reviews do not meet their expectations and they run into problems implementing the schedule. The major reason for this is they did not get buy-in from the stakeholders. After you create the first draft of the schedule, make sure to review it with your team members. They should review the schedule to be sure they agree with the transition you made from duration estimates to actual calendar dates. You will also want to be sure that you have the team's vacation, down times, and other commitments incorporated in your plan.

As you are still awake at 2 a.m. you can contemplate why you didn't check with the functional managers before you finalized the schedule. In a matrix organization you will need to follow-up with the functional manager to ensure that you haven't incorrectly or double scheduled their people. There will be competing priorities and the functional manager will decide if the person will be available to work on your project when you have the activity scheduled. As you make adjustments, you may also need to negotiate changes in the percent availability of resources and schedule dates. After you complete this give and take, get the functional manager's signature. You have their commitment.

The best way to turn your dream into a nightmare is to plan and execute your project in a vacuum. Remember that other projects may impact yours. You need to be sure that there are no issues with dependencies on other interrelated projects and their resource usage. Managing these issues now during planning will save a lot of heartache during execution. You need to check for both resource and schedule conflicts. Know what key deliverables you need from other projects. Know when they are due and communicate, communicate, communicate. The more information you have, the better.

Conclusion

Schedule development is more complicated than most project managers think. Following the process will help get you going in the right direction. The tricks presented will take you the rest of the way. With these in your bag of project management tricks, you will sleep more soundly and avoid seeing Dracula and his friends in your dreams.

References

Mulcahy, Rita. 2001. PMP Exam Prep. Minneapolis, MN: RMC Publications.

Pritchard, Carl. 2001. Project Management for Business Professionals, Edited by Joan Knutson, Chapter 6, Schedule Management. New York: John Wiley & Sons, Inc.

Project Management Institute. 2000. A Guide to the Project Management Body of Knowledge (PMBOK® Guide) - 2000 Edition. Newtown Square, PA: Project Management Institute.

This material has been reproduced with the permission of the copyright owner. Unauthorized reproduction of this material is strictly prohibited. For permission to reproduce this material, please contact PMI or any listed author.

Proceedings of the Project Management Institute Annual Seminars & Symposium
October 3–10, 2002 • San Antonio, Texas, USA

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