Standard Deviation of Activity Calculator

✖A Pessimistic Time is the longest time that an activity could take if everything is wrong.ⓘ Pessimistic Time [t_p]			+10% -10%
✖Optimistic Time is the shortest possible time to complete the activity if all goes well.ⓘ Optimistic Time [t₀]			+10% -10%

✖The Standard Deviation is a measure of how spread out numbers are.ⓘ Standard Deviation of Activity [σ]

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Formula

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Standard Deviation of Activity

Formula

`"σ" = ("t"_{"p"}-"t"_{"0"})/6`

Example

`"1.333333"=("10d"-"2d")/6`

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Standard Deviation of Activity Solution

STEP 0: Pre-Calculation Summary

Formula Used

Standard Deviation = (Pessimistic Time-Optimistic Time)/6
σ = (t_p-t₀)/6
This formula uses 3 Variables

Variables Used

Standard Deviation - The Standard Deviation is a measure of how spread out numbers are.
Pessimistic Time - (Measured in Day) - A Pessimistic Time is the longest time that an activity could take if everything is wrong.
Optimistic Time - (Measured in Day) - Optimistic Time is the shortest possible time to complete the activity if all goes well.

STEP 1: Convert Input(s) to Base Unit

Pessimistic Time: 10 Day --> 10 Day No Conversion Required
Optimistic Time: 2 Day --> 2 Day No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

σ = (t_p-t₀)/6 --> (10-2)/6

Evaluating ... ...

σ = 1.33333333333333

STEP 3: Convert Result to Output's Unit

1.33333333333333 --> No Conversion Required

FINAL ANSWER

1.33333333333333 ≈ 1.333333 <-- Standard Deviation

(Calculation completed in 00.004 seconds)

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Credits

Created by Chandana P Dev

NSS College of Engineering (NSSCE), Palakkad

Chandana P Dev has created this Calculator and 500+ more calculators!

Verified by Mithila Muthamma PA

Coorg Institute of Technology (CIT), Coorg

Mithila Muthamma PA has verified this Calculator and 700+ more calculators!

< 17 Project Evaluation and Review Technique Calculators

Optimistic Time given Expected Time

Go Optimistic Time = (6*Mean Time)-(4*Most Likely Time)-Pessimistic Time

Mean or Expected Time

Go Mean Time = (Optimistic Time+(4*Most Likely Time)+Pessimistic Time)/6

Most Likely Time given Expected Time

Go Most Likely Time = (6*Mean Time-Optimistic Time-Pessimistic Time)/4

Standard Deviation given Probability Factor

Go Standard Deviation = (Scheduled Time-Mean Time)/Probability Factor

Scheduled Time given Probability Factor

Go Scheduled Time = (Standard Deviation*Probability Factor)+Mean Time

Expected Time given Probability Factor

Go Mean Time = Scheduled Time-(Standard Deviation*Probability Factor)

Probability Factor

Go Probability Factor = (Scheduled Time-Mean Time)/Standard Deviation

Pessimistic Time given Expected Time

Go Pessimistic Time = 6*Mean Time-Optimistic Time-4*Most Likely Time

Earliest Expected Occurrence Time of Event j

Go Earliest Occurrence Time of j = Earliest Occurrence Time of i+Duration of i-j

Earliest Expected Occurrence Time of Event i

Go Earliest Occurrence Time of i = Earliest Occurrence Time of j-Duration of i-j

Expected Time of Activity i-j

Go Duration of i-j = Earliest Occurrence Time of j-Earliest Occurrence Time of i

Slack of Event i or j

Go Slack of an Event = LOT of Event j-Earliest Occurrence Time of j

Optimistic Time given Standard Deviation

Go Optimistic Time = -(6*Standard Deviation-Pessimistic Time)

Standard Deviation of Activity

Go Standard Deviation = (Pessimistic Time-Optimistic Time)/6

Pessimistic Time given Standard Deviation

Go Pessimistic Time = 6*Standard Deviation+Optimistic Time

Least Allowable Occurrence Time of Event i

Go LOT of Event i = LOT of Event j-Duration of i-j

Least Allowable Occurrence Time of Event j

Go LOT of Event j = LOT of Event i+Duration of i-j

Standard Deviation of Activity Formula

Standard Deviation = (Pessimistic Time-Optimistic Time)/6
σ = (t_p-t₀)/6

What is Central Limit Theorem?

Central Limit Theorem states that if a project consist of large number of activities, where each activity has its own mean time, standard deviation and variance then the whole distribution of time for the project will be approximately a normal distribution.

What is Critical Path?

The time wise longest path is known as the critical path. Ay delay in this path will cause delay for the whole project.

How to Calculate Standard Deviation of Activity?

Standard Deviation of Activity calculator uses Standard Deviation = (Pessimistic Time-Optimistic Time)/6 to calculate the Standard Deviation, The Standard Deviation of Activity formula is defined as a measurement of uncertainty which is approximately one-sixth of the time range. Standard Deviation is denoted by σ symbol.

How to calculate Standard Deviation of Activity using this online calculator? To use this online calculator for Standard Deviation of Activity, enter Pessimistic Time (t_p) & Optimistic Time (t₀) and hit the calculate button. Here is how the Standard Deviation of Activity calculation can be explained with given input values -> 1.333333 = (864000-172800)/6.

FAQ

What is Standard Deviation of Activity?

The Standard Deviation of Activity formula is defined as a measurement of uncertainty which is approximately one-sixth of the time range and is represented as σ = (t_p-t₀)/6 or Standard Deviation = (Pessimistic Time-Optimistic Time)/6. A Pessimistic Time is the longest time that an activity could take if everything is wrong & Optimistic Time is the shortest possible time to complete the activity if all goes well.

How to calculate Standard Deviation of Activity?

The Standard Deviation of Activity formula is defined as a measurement of uncertainty which is approximately one-sixth of the time range is calculated using Standard Deviation = (Pessimistic Time-Optimistic Time)/6. To calculate Standard Deviation of Activity, you need Pessimistic Time (t_p) & Optimistic Time (t₀). With our tool, you need to enter the respective value for Pessimistic Time & Optimistic Time and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

How many ways are there to calculate Standard Deviation?

In this formula, Standard Deviation uses Pessimistic Time & Optimistic Time. We can use 1 other way(s) to calculate the same, which is/are as follows -

Standard Deviation = (Scheduled Time-Mean Time)/Probability Factor

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