After we define the lowest level of activities in an activity list, each activity is reviewed and evaluated to determine the duration (how long it will take to accomplish from beginning to end) and what resources (e.g., human resources, materials, facilities, and equipment) are needed. An estimate is an educated guess based on knowledge, experience, and inference—the process of deriving conclusions based on assumptions. The accuracy of the estimate is related to the quality
of the knowledge and how that knowledge is applied. The person with the most knowledge may not be the most objective person to provide duration estimates. The person responsible for the work may also want to build in extra time. Therefore, multiple inputs into the duration estimate and a more detailed WBS help reduce bias—the making of decisions based on a prejudged perspective. It is of high importance here to highlight how a milestone is different from an activity. A milestone is a
significant point or event in a project. Milestones have zero duration because they represent a significant point or event. A milestone list identifies all project milestones and indicates whether the milestone is mandatory, such as those required by contract, or optional, such as those based on historical
information[1]. The unit of time used to develop the
activity duration is a function of the level of detail needed by the user of the schedule. The larger and more complex the project, the greater the need for detail, which usually translates into shorter durations for activities. However, it is common to use two types of units – one is days or weeks for activities, and hours to display the work hours. In this textbook, we can elaborate on five types of estimation methods:
In the three-point estimation method, two distributions are possible – triangular and beta. In triangular distribution, all three duration estimates get the same weight. In a beta distribution, the realistic estimate gets four-sixths of the weight whereas the other two estimates have one-sixth of the weight. Triangular distribution: Beta distribution: Let’s estimate the duration of the “1.3 Preparation of Project Charter” sub-activities. Our team gathered together in a meeting to review and discuss alternative durations. We also consulted subject matter experts who work in relevant departments in our organization and also external stakeholders who have an interest and/or power. Our organization and the team had implemented software and website development projects as well as several mobile application development projects. Therefore, we have reports including information regarding the realized durations and lessons learned. So, we can start with analogous estimating first. As we have already worked on similar projects, that would facilitate the estimation process both for schedule and budget. We can place the historical information on the Most Likely column. Based on the expert judgment, lessons learned, and discussions during our team meeting, we determined pessimistic and optimistic durations in Table 7.2. Table 7.2: Estimating Activity Duration by Applying Three-Point Estimate Method
The computation of the duration for Activity 1.3.2 is shown below: We can roll the duration estimates down or up to the nearest integral number.
What is most likely time in project management?Most likely time - the completion time having the highest probability. Note that this time is different from the expected time. Pessimistic time - the longest time that an activity might require. Three standard deviations from the mean is commonly used for the pessimistic time.
What includes the actual amount of time spent working on an activity plus elapsed time?Duration includes the actual amount of time spent working on an activity plus elapsed time.
What is the amount of time an activity may be delayed without delaying a succeeding activity or the project finish date multiple choice milestones slack scope management?Total float is how long an activity can be delayed without putting off the project completion date. On a critical path, the total float is zero. Total float is often known as the slack. You can calculate it by subtracting the Early Start date of the activity from its Late Start Date.
Which of the following is used to display a project schedule?A Gantt chart is a commonly used graphical depiction of a project schedule. It's a type of bar chart showing the start and finish dates of a project's elements such as resources, planning, and dependencies.
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