PMP Study - Part 11 - Estimating Activity Resources & Durations

In Parametric Estimating what is the definition of Duration?

How long an activity is expected to take with the labor available

In Parametric Estimating what is the formula for a single human resource carrying out an activity?

Quantity of Work x Productivity Rate = Duration

What is Parametric Estimating?

o1) Uses a mathematical formula that takes into account various factors that affect durations such as - Quantity of work to be performed - Number of resources assigned to the task - Productivity rates of the resources assigned

What are the two steps related to resource assumptions?

1) Record resource assumptions in the resource requirements list as 2) Review assumptions regularly

In Parametric Estimating what is the formula for when more then one resource is applied to an activity?

(Quantity of Work x Productivity Rate) / No. of resources = Duration

What are the Inputs for the Estimating Activity Duration process? (6 points)

1) Activity list - Identifies all the work tasks that will be included in the project schedule 2) Activity attributes - Describes task-level assumptions, constraints, responsibilities and locations 3) Activity resource requirements - Describes the type and quantities of resources needed for specific activities 3) Resource calendar - Shows people, equipment and materials that can be assigned to activities 4) Project scope statement - Includes the deliverables, constraints and assumptions that apply to the overall project and specific milestones or limitations imposed by the project's customer including deadlines and length of reporting periods 5) Enterprise environmental factors - External environmental and internal organizational factors that can affect resource availability and work durations 6) Organisational process assets - An organization's rules, method and practices for conducting work can affect how long project activities will take and historical data can help create accurate duration estimates

What are the Inputs to the Estimate Activity Resource process? (4 points)

1) Activity list & Activity attributes - Important starting points for estimating resources as they identify what must be done during the project and activity attributes provide details on each activity to further define resource requirements 2) Enterprise Environmental Factors - Help determine what resources you can use for a project, as well as when and how 3) Organisational Process Assets - Help determine what resources you can use for a project, as well as when and how 4) Resource calendars - Most important input for estimating resources as they provides details on the availability of human resources for the duration of the project and may also provide information on availability of material resources such as equipment and space

What are the 3 steps to bottom-up estimating?

1) Decompose activities into more detail 2) Estimate resources for each piece of work 3) Aggregate all estimates in to a total quantity - includes recording resource availability & resource dependencies

What are the Outputs of the Estimating Activity Duration process? (2 points)

1) Duration estimates 2) Project document updates

What tools & techniques are used during the Estimating Activity Duration process? (5 points)

1) Expert Judgment 2) Analogous estimating 3) Reserve analysis 4) Parametric estimating 5) Three-point estimates

What tools & techniques are used during the Estimate Activity Resource process and their purpose? (5 points)

1) Expert judgment - Used to verify the accuracy of estimates calculated through other techniques 2) Alternative analysis - Used to compare different ways of completing scheduled activities and determine the best use of resources 3) Published estimating date - Assists in making accurate resource estimates by giving a frame of reference to work from for quantifying resources 4) Project management software - Helps to plan, organize and manage resources 5) Bottom-up estimating - Best used when project is complex or new to an organisation and generally the most accurate estimating technique however generally the slowest & most costly estimating technique

Why is it important to estimate activity resources & durations? (4 points)

1) Helps create realistic schedule and budget 2) Affects procurement and contracts 3) Ensures projects are properly resourced 4) Helps manage stakeholder expectations

What are examples of appropriate categories to use in a Resource Breakdown Structure (RBS)? (5 points)

1) Human resources 2) Logistics 3) Consumables 4) Materials 5) Equipment

Why is it important to record resource assumptions? (3 points)

1) Monitoring - can affect performance monitoring - e.g. if a task is taking too long the assumptions can identify the problem 2) Controlling - having identified a problem, performance adjustments can be made to allow the project to be more efficient 3) Closing - can provide insights during post-project assessments

What are the two key sources of expert judgment during the Estimating Activity Duration process?

1) Project managers who have led similar projects 2) Project team members who have worked on similar projects

What are examples of risks that might require reserve time to be added to a project duration?

1) Resource is used in another project 2) Possibility of bad weather 3) Likely to have sick days 4) New requirements discovered 5) Need to find and fix bugs

What type of information is needed to estimate resources? (4 points)

1) Type of resources - physical and human resources 2) Quantity of resources - critical for budget and to a lesser degree scheduling 3) Required skill sets to complete activity 4) Project team roles and availability - critical for scheduling

What are the Outputs of the Estimate Activity Resource process? (3 points)

1) Updated project documents 2) Activity resource requirement list 3) Resource Breakdown Structure (RBS)

Why is a Resource Breakdown Structure (RBS) useful? (4 points)

1) Visually simple - shows resource information at a glance 2) Breaks resources into categories 3) Helps organise project schedule & report on resource utilisation 4) Can be used for cost reporting if finance information is included

What should be included in the Activity Resource Requirements List? (8 points)

1) WBS activity code 2) WBS activity name 3) Resource description 4) No. required 5) Resource assumptions 6) Resource availability 7) Resource dependencies 8) Final row - identifies total resources needed for activity

What are the two ways in which estimating resources is usually coordinated closely with the budget?

1) What will the project cost - start out with a rough breakdown of overall estimated costs - further investigation used to determine actual resources needed and the associated cost 2) What the project can afford - working with a limited set budget means resources are assigned according to what can be afforded which affects resource type and level engaged

What is a Resource Breakdown Structure (RBS)?

A Hierarchical diagram of resources required for a project

What is a three-point estimate?

A weighted average of an - Optimistic / best-case duration - Most likely duration - Pessimistic / worst-case duration

What is Analogous Estimating?

Combines expert judgment and historical information from similar completed projects - the past project is the "analogy" compared to the new project - also known as "top-down" estimating

What is Reserve Analysis?

Incorporating additional time - called contingency reserves, time reserves or buffers - into the overall project duration to create buffers in the schedule where delays are extremely likely

What is a composite resource calendar?

One that provides scheduling information for human, skill and material resources

Quantity of Work x Productivity Rate = Duration What is this formula used for?

Parametric Estimating - Estimating an activity duration when a single human resource is carrying out an activity

(Quantity of Work x Productivity Rate) / No. of resources = Duration What is this formula used for?

Parametric Estimating - Estimating an activity duration when more then one resource is applied to an activity

When would Analogous Estimating be most useful?

Particularly useful in early stage of planning as it can provide a ballpark figure to work with

What are the steps to creating a three-point estimate? (7 points)

Step 1 - Record an optimistic estimate - based on all conditions being favorable given expert judgment and analogous estimating results Step 2 - Record a most likely estimate - based on typical conditions and historical information Step 3 - Record a pessimistic estimate - based on how foreseeable negative conditions might delay an activity Step 4 - Assign weights to estimates - Weights should reflect probability that each estimate will be accurate e.g. on a scale of 1-4 an estimate with a weight of 4 is 4 times more likely to happen as an estimate with a weight of 1 Step 5 - Multiply each estimate by assigned weight Step 6 - Total the weighted durations Step 7 - Divide sum of weighted durations by sum of weights

In Parametric Estimating what is the definition of Effort?

The amount of labor or total number of billable hours invested in an activity - used when calculating costs

Why is it important to have quality inputs for the Estimating Activity Duration process?

The quality of information provided in the Inputs affects the accuracy of a project manager's duration estimates

What is the main restriction when using Analogous Estimating?

The reliability depends on how similar the projects are, how much experience the sources of expert judgment have and whether the team members have similar levels of experience in as those in the previous project

What is the purpose of three-point estimating?

To builds on information gained from Parametric Estimating to arrive at a more reliable estimate

In Parametric Estimating where does the Productivity rate come from?

Using analogous estimating and expert judgment