Project Time Management II
This is in continuation of the article Project Time management I .This article will cover the remaining processes of this knowledge area.
Estimating Activity Resources
The term resources do not mean just people; it means all the physical resources required to complete the project.
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Inputs of Estimating Activity Resources
The only inputs not covered so far are resource calendars and risk register.
Activity cost estimates
Estimate Activity Resources should be closely coordinated with the Activity cost estimates, because—whether people or material; both are typically the largest expense on any project. Identifying the resources becomes a critical component of the project planning process so estimates and the total project cost can be accurately derived.
Resource calendars
It describes the time frames in which resources (both human and material) are available. They look at a particular resource or groups of resources and their skills, abilities, quantity, and availability. For instance a project calls for an actuarial resource and the person assigned is on an extended vacation in May. The resource calendar would show this person’s vacation schedule. Resource calendars also examine the quantity, capability, and availability of equipment and material resources that have a potential to impact the project schedule
Tools and Techniques of Estimating Activity Resources
Alternatives analysis
Many times, you can accomplish an activity in more than one way, and alternatives analysis helps decide among the possibilities. For example, an ordinary car drives on the same roads a six-figure sports car travels. The sports car has a lot more features than the ordinary car, it’s faster, more comfortable, and it has a visual appeal that the other car lacks. The sports car might be the valid resource choice for the project, but you should consider all the alternatives.
The same idea applies to human resources in that you might apply senior-level resources versus junior-level resources, or you could add resources to speed up the schedule. You may also use make-or-buy analysis when determining alternative resources.
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Published estimating data
Estimating data might include organizational guidelines, industry rates or estimates, production rates, and so on. For example, your organization might have established price agreements with vendors that outline rates by resource types, or there might be industry estimates for production rates for your particular activity.
Bottom-up estimating
This is a process of estimating individual schedule activities or costs and then adding these together to come up with a total estimate for the work package. Here you estimate every schedule activity individually and then add them all together, to come up with a total. This is an accurate means of estimating provided the estimates at the schedule activity level are accurate. However, it takes a considerable amount of time to perform bottom-up estimating because every activity must be assessed and estimated accurately to be included in the bottom-up calculation. The smaller and more detailed the activity, the greater the accuracy and cost of this technique.
Project management software
It can help plan, organize, and estimate resource needs and document their availability. It might also help you to produce resource breakdown structures, resource rates, resource calendars, and availability.
Outputs of Estimating Activity Resources
Activity resource requirements
It describes the types of resources and the quantity needed for each activity associated with a work package. You should prepare a narrative description for this output that describes how you determined the estimate, including the information you used to form your estimate and the assumptions you made about the resources and their availability. The information from this output is used in the next process (Estimate Activity Durations) to determine the length of time each activity will take to complete.
Resource breakdown structure (RBS)
It is much like an organizational breakdown structure only the RBS lists the resources by category and type. There may be several categories of resources, including man power, hardware, equipment, supplies, and so on. Type describes the types of resources needed, such as skill levels or quality grades of the material and so on.
Estimating Activity Durations
This estimation attempts to estimate the work effort, resources, and number of work periods needed to complete each activity. The activity duration estimates are the primary output of this process. When estimating activity duration, make certain to include all the time that will elapse from the beginning of the activity until the work is completed.
Here, estimates typically start at a fairly high level, and as more and more details are known about the deliverables and their associated activities, the estimates become more accurate this is known as progressive elaboration.
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Tools and Techniques of Estimating Activity Durations
Expert Judgment
In this case, team members use expert judgment because of their experience with similar activities in the past. You should be careful with these estimates, though, because they are subject to bias and aren’t based on any scientific means. Your experts should consider that resource levels, resource productivity, resource capability, risks, and other factors can impact estimates. Its good practice to combine expert judgment with historical information and use as many experts as you can.
Analogous Estimating
Analogous estimating, also called top-down estimating, is a form of expert judgment. This technique is frequently used to estimate a value when there is limited amount of information in early phases of the project, thus it uses historical information (based on a similar project done in past) and expert judgment.
Parametric estimating
It is a quantitatively based estimating method that multiplies the quantity of work by the rate. The best way to describe it is with an example. Ben has 10,000 meters of new cable to run. He knows from past experience it takes 2 hour to install 100 meters. Using this measurement, he can determine an estimate for this activity of 200 hours to run the new cable. Therefore, the cable activity duration estimate is 200 hours.
Three-point estimates
This estimate is also known as PERT (Program Evaluation and Review Technique). The three estimates used in this technique are the most likely estimate (M), an optimistic estimate (O), and a pessimistic estimate (P).
Depending on the assumed distribution of values within the range of three estimates the expected duration, E can be calculated using the following formula.
- Triangular distribution
Expected Duration (E) = (O+M+P)/3
- Beta Distribution
Expected Duration (E) = (O+4*M+P)/6
Reserve Analysis
Reserve time—also called buffers, time reserves, or contingency reserve in the PMBOK® Guide —means a portion of time that is added to the activity to account for schedule risk or uncertainty. It can also be added as a percentage of time or a set number of work periods to the activity or the overall schedule. Considering previous example where it will take 200 hours to run new cable based on the quantitative estimate. Ben knows that sometimes it hits problem areas when running the cable. To make sure not to impact the project schedule, he builds in a reserve time of 10 percent of his original estimate to account for the problems he might encounter. This brings the activity duration estimate to 220 hours for this activity.
Outputs of Estimating Activity Durations
The primary output of this process is the activity duration estimates. These estimates are an estimate of the required work periods needed to complete the activity. This is a quantitative measure usually expressed in hours, weeks, days, or months.
The other output of Estimate Activity Durations is project document updates. Some of the information that may need revisited and updated as a result of this process is the activity attributes and the assumptions you made regarding resource availability and skill levels.
Develop Schedule
Develop Schedule, along with Estimate Activity Resources and Estimate Activity Durations, is repeated several times before you actually come up with the project schedule. Most project management software programs today can automatically build a schedule for you once you’ve entered the needed information for the activities. The project schedule, once it’s approved, serves as the schedule baseline for the project that you can track against in later processes.
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Inputs of Develop Schedule
You can see how important it is to perform all the Planning processes accurately because the information you derive from almost every process in the Planning group is used somewhere else in Planning, many of them here. Your project schedule will reflect the information you know at this point in time.
Outputs of Develop Schedule
Project Schedule
The purpose of the Develop Schedule process is to determine the start and finish dates for each of the project activities. One of the primary outputs of this process is the project schedule, which details this information as well as the resource assignments. However, depending on the size and complexity of your project or your organization’s culture, the resource assignments and determining the start and finish dates might not be completed yet. In that the case, the project schedule is considered preliminary until the resources are assigned to the activities.
Schedule Baseline
Schedule baseline is the final, approved version of the project schedule with baseline start and baseline finish dates and resource assignments. The PMBOK® Guide notes that the schedule baseline is a designated version of the project schedule that’s derived from the schedule network analysis. The approved project schedule becomes a part of the project management plan.
You will continue to revisit processes throughout the project to refine and adjust. You wouldn’t want to return to the Planning process at the conclusion of the project, for example, but keep in mind that the Planning, Executing, and Monitoring and controlling process groups are iterative, and it’s not unusual to have to revise processes within these process groups as you progress on the project. Be certain to obtain sign-off of the project schedule and provide your stakeholders and project sponsor with regular updates.
Schedule Data
The schedule data refers to documenting the supporting data for the schedule. The minimum amount of information in this output includes the milestones, schedule activities and activity attributes, and the assumptions and constraints regarding the schedule. You should document any other information that doesn’t necessarily fit into the other categories. Alternative schedules or contingency schedule reserves can also be included in the schedule data section.
Control Schedule
The Control Schedule process involves determining the status of the project schedule, determining whether changes have occurred or should occur, and influencing and managing schedule changes. The key benefit of this process is that it provides the means to recognize deviation from the plan and take corrective and preventive measure and thus minimizing the risk.
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In the Control Schedule process, because you’re dealing with time issues, it’s imperative that you act as quickly as possible to implement corrective actions so that the schedule is brought back in line with the plan and the least amount of schedule delay as possible is experienced.
Outputs of Control Schedule
Changes to the cost baseline may be necessary when you’ve used a schedule compression or crashing technique. Changes to approved schedule start and end dates in the schedule baseline are called revisions. These generally occur as a result of a project scope change, or changes to activity estimates, and might result in a schedule baseline update. This results in schedule baseline updates. Which means a new schedule baseline is established that reflects the changed project activity dates. Once the new baseline is established, it is used as the basis for future performance measurements.
Before re-baselining a schedule, ensure two things first having it approved by the project sponsor and second is archiving a copy of the original baseline and schedule. Make a backup copy of the original schedule so that you have a record of the original baseline as a reference. Even though some project management software allows you to save several baselines plus the original, it’s still good practice to make a backup copy of the original. Changes to the project schedule might or might not require updates to other elements of the project plan as well.
The project document updates output may require updates to either the schedule data or project schedule or both. For example, project schedule network diagrams require updates as a result of schedule model data updates.
Questions & Answers
- Sandy, the project manager of the new project, knows that the project’s primary constraint is quality. To make certain the project team members don’t feel too pressed for time and to avoid schedule risk, he decide to use which of the following activity estimating tools?
- Three-point estimates
- Analogous estimating
- Reserve analysis
- Parametric estimating
Correct Answer: C. Reserve analysis takes schedule risk into consideration and adds a percentage of time or additional work periods to the estimate to prevent schedule delays.
- Anita has been hired as the contract project manager for Excess Fun Club. She was assigned the project to design an Internet wine club for its customers. One of the activities for this project is the installation and testing of several new servers. She knows from past experience it takes about 20 hours per server to accomplish this task. So for installing 10 new servers, she estimated the activity to take 200 hours. Which of the estimating techniques was used by her?
- Parametric estimating
- Analogous estimating
- Bottom-up estimating
- Reserve analysis
Correct Answer: D. Parametric estimating multiplies a known element—such as the quantity of materials needed—by the time it takes to install or complete one unit of materials. In this case, 10 servers multiplied by 20 hours per server gives a 200-hour total duration estimate.
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