Probability Factor Calculator

✖Scheduled Time is the time which is made as per the experience and practice by the creator of the project.ⓘ Scheduled Time [T_s]			+10% -10%
✖Mean Time, also called expected time is the time needed to complete an activity.ⓘ Mean Time [t_e]			+10% -10%
✖The Standard Deviation is a measure of how spread out numbers are.ⓘ Standard Deviation [σ]			+10% -10%

✖The probability Factor is a term used to find the probability of a project getting completed in the expected time.ⓘ Probability Factor [Z]

⎘ Copy

👎

Formula

✖

Probability Factor

Formula

`"Z" = ("T"_{"s"}-"t"_{"e"})/"σ"`

Example

`"2.030075"=("6.7d"-"4d")/"1.33"`

Calculator

LaTeX

Reset

👍

Download Project Evaluation and Review Technique Formulas PDF

Probability Factor Solution

STEP 0: Pre-Calculation Summary

Formula Used

Probability Factor = (Scheduled Time-Mean Time)/Standard Deviation
Z = (T_s-t_e)/σ
This formula uses 4 Variables

Variables Used

Probability Factor - The probability Factor is a term used to find the probability of a project getting completed in the expected time.
Scheduled Time - (Measured in Day) - Scheduled Time is the time which is made as per the experience and practice by the creator of the project.
Mean Time - (Measured in Day) - Mean Time, also called expected time is the time needed to complete an activity.
Standard Deviation - The Standard Deviation is a measure of how spread out numbers are.

STEP 1: Convert Input(s) to Base Unit

Scheduled Time: 6.7 Day --> 6.7 Day No Conversion Required
Mean Time: 4 Day --> 4 Day No Conversion Required
Standard Deviation: 1.33 --> No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

Z = (T_s-t_e)/σ --> (6.7-4)/1.33

Evaluating ... ...

Z = 2.03007518796993

STEP 3: Convert Result to Output's Unit

2.03007518796993 --> No Conversion Required

FINAL ANSWER

2.03007518796993 ≈ 2.030075 <-- Probability Factor

(Calculation completed in 00.006 seconds)

You are here -

Home » Engineering » Civil » Construction Practice, Planning and Management » Project Evaluation and Review Technique » Probability Factor

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

Probability Factor Formula

Probability Factor = (Scheduled Time-Mean Time)/Standard Deviation
Z = (T_s-t_e)/σ

What is an Event and an Activity?

An event represents the accomplishment of some task. In a network diagram, beginning and ending of an activity are represented as events. Each event is represented as a node in a network diagram. An event does not consume any time or resource. Each network diagram starts with an initial event and ends at a terminal event.
An activity is a physically identifiable part of a project, which consumes both time and resources. Activity is represented by an arrow in a network diagram. The head of an arrow represents the start of activity and the tail of arrow represents its end. Activity description and its estimated completion time are written along the arrow.

What is Central Limit Theorem and Critical Path?

Central Limit Theorem: The theorem states that a project consists of a large number of activities, where each activity has its own mean time (te), standard deviation (σ), variance (σ2) and also its own ß-distribution curve.
Critical Path: The time-wise longest path is the critical path. In this path, any type of delay in any event will cause a delay in the project. These are shown by double lines or dark lines in a network.

How to Calculate Probability Factor?

Probability Factor calculator uses Probability Factor = (Scheduled Time-Mean Time)/Standard Deviation to calculate the Probability Factor, The Probability Factor formula is defined as a term used to find the probability of the occurrence of an event or completion of an event at an expected time. Probability Factor is denoted by Z symbol.

How to calculate Probability Factor using this online calculator? To use this online calculator for Probability Factor, enter Scheduled Time (T_s), Mean Time (t_e) & Standard Deviation (σ) and hit the calculate button. Here is how the Probability Factor calculation can be explained with given input values -> 2.030075 = (578880-345600)/1.33.

FAQ

What is Probability Factor?

The Probability Factor formula is defined as a term used to find the probability of the occurrence of an event or completion of an event at an expected time and is represented as Z = (T_s-t_e)/σ or Probability Factor = (Scheduled Time-Mean Time)/Standard Deviation. Scheduled Time is the time which is made as per the experience and practice by the creator of the project, Mean Time, also called expected time is the time needed to complete an activity & The Standard Deviation is a measure of how spread out numbers are.

How to calculate Probability Factor?

The Probability Factor formula is defined as a term used to find the probability of the occurrence of an event or completion of an event at an expected time is calculated using Probability Factor = (Scheduled Time-Mean Time)/Standard Deviation. To calculate Probability Factor, you need Scheduled Time (T_s), Mean Time (t_e) & Standard Deviation (σ). With our tool, you need to enter the respective value for Scheduled Time, Mean Time & Standard Deviation and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

Home

FREE PDFs

🔍 Search