This document discusses estimating activity duration for projects. It provides guidance on properly estimating each activity duration by giving estimators enough information and ensuring assumptions are recorded. It also discusses common estimation techniques like analogous, parametric, and three-point estimating which involve determining a range of possible durations using best, worst, and most likely case scenarios. The document emphasizes preventing padding of estimates and formulating contingency reserves to account for risks and uncertainties.

1. Estimate Activity Duration
Aqeel Wahab Siddiqui
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2.  I have no idea how long it will take.
 I do not even know what I am being asked to do.
 So what do I say?
 I will take my best guess and double it.
Padding?
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3.  Provide the team with enough Information to properly estimate each
activity.
 Let those doing the estimating know how refined their estimates must be.
 Complete a sanity check of the estimates.
 Prevent Padding
 Formulate a reserve
 Make sure assumptions made during estimating are recorded for later
review.
How is Estimating Done?
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4. Estimate Activity Duration
Once the activities are defined
and sequenced and the type and
quantity of resources required for
each activity are identified, the
next step is to estimate how much
time each activity will take.
Estimate Activity Duration is the
process of approximating the
number of work periods needed
to complete Individual activities
with estimated resources.
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5. Project Management Plan
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6. AQEEL WAHAB SIDDIQUI
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7. Scope Statement
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8. Work Breakdown Structure
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9. ID Activity Description of Work
Activity List
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11. Milestone List  It is significant point to achieve
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12. Project Team
Assignment
This document contains project
team members mentioned in the
front of each activity of the project.
For this purpose we just update
Activity Attributes document
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13. Resource Calendar , Requirements and Risk Register
You need resource calendar which contains the availability of resources
data whereas in Resource Requirements explain the skills needed for
the activity to complete well on time. For example, if additional or lower
skilled resources are assigned to an activity, there may be reduced
efficiency or productivity due to increased communication, training and
coordination needs leading to a longer duration estimate.
Project Risks may impact resource selection and availability.
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14.  It Can force people time using a one-point estimate, the estimator submits
one estimate per activity.
 Negative effects:
– Force people into padding their estimates.
– It hides Important Information about risks and uncertainties from the project
manager.
– When a person estimates that an activity will take 20 days and It is completed in 15
days, It can make the person who provided the estimate look untruthful and
untrustworthy.
– It often results in the estimators working against the project manager to protect
themselves.
One-Point Estimating
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15.  Analogous estimating can be done for a project (e.g., the last five
projects similar to this one each took eight months, so this one should
also) or an activity (e.g., the last two times this activity was completed
each took three days: since we have no other information to go on,
we will use three days as the estimate for this activity and review the
estimate when more details become available.
Analogous Estimating
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16.  Parametric estimating 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. Suppose you are working on a companywide network
upgrade project. This requires you to run new cable to the switches on every
floor in the building. You can use parametric estimates to determine activity
duration estimates by taking a known element—in this case, the amount of
cable needed and multiplying it by the amount of time it takes to install a
unit of cable to come up with an estimate. In other words, suppose you have
10,000 meters of new cable to run. You know from past experience it takes 1
hour to install 100 meters. Using this measurement, you can determine an
estimate for this activity of 100 hours to run the new cable. Therefore, the
cable activity duration estimate is 100 hours.
Parametric Estimating
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1. Identify an item to be estimated.
2. Estimate the number of items.
3. Estimate the effort per item.
4. Multiply effort per item by number of items to
determine the total effort.
Parametric method (Cont.)
For example, if the assembly of one library shelving stack takes an hour
and a half and there are 40 stacks to assemble then the total effort is 60
hours.
Steps in deriving the estimate:

18.  As we know, things do not always go according to plan. Therefore, it is
often best to state estimates in a range using three-point estimates.
Analyzing what could go right and what could go wrong can help
estimators determine an expected range for each activity.
 Triangular Distribution:
 Beta Distribution:
 Beta Activity Standard Deviation:
Three-Point Estimating
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19. Activity P M O Triangular Distribution
A 47 27 14
B 89 60 41
C 48 44 39
D 42 37 29
Exercise:
Complete the chart using the previously described formulas.
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20. Activity P M O Triangular Distribution
A 47 27 14 29.333
B 89 60 41 63.333
C 48 44 39 43.666
D 42 37 29 36
Exercise:
Complete the chart using the previously described formulas.
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21. Activity P M O Expected Activity
Duration
(Beta
Distribution)
Beta Activity
Standard
Deviation
Range of the Estimate
A 47 27 14
B 89 60 41
C 48 44 39
D 42 37 29
Exercise:
Complete the chart using the previously described formulas.
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22. Activity P M O Expected Activity
Duration
(Beta
Distribution)
Beta Activity
Standard
Deviation
Range of the Estimate
A 47 27 14 28.167 5.500 22.667 to 33.667, or 28.167
+/- 5.550
B 89 60 41 61.667 8.000 53.667 to 69.667, or 61.667
+/- 8.000
C 48 44 39 43.833 1.500 42.333 to 45.333, or 43.833
+/- 1.500
D 42 37 29 36.500 2.167 34.333 to 38.667 , or 36.500
+/- 2.167
Exercise:
Complete the chart using the previously described formulas.
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23. Data Analysis
 Alternative analysis I used to compare various levels of resource
capability or skills.
 Reserve analysis is used to determine the amount of contingency and
manage reserve needed for the project.
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24. Decision Making
 Decision making techniques that can be used in this process includes
voting. In this technique project manager ask team members to show
their level of support for a decision by holding up a closed fist (1 to 5
fingers). If a team member holds up fewer than three fingers, the
team member is given the opportunity to discuss any objections with
the team.
 The Project manager continues the fist-of-five process until the team
achieves consensus (everyone holds up three or more fingers) or
agrees to move on to the next decision.
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25. Meetings
 The project team may hold meetings to estimate activity duration.
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26.  Do not forget
 Click the subscribe button
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