Critical Path Method (CPM) and Activity Duration Analysis

This set of vocabulary flashcards covers the fundamental terms, conventions, and formulas used in the Critical Path Method (CPM) and probabilistic activity duration analysis as presented in the lecture notes.

Critical Path Method (CPM)

A technique used for project time analysis and estimating activity durations, often incorporating probabilistic methods to manage uncertainties.

Beginning-of-the-Day (BD) convention

A calendar convention where an activity with a 4-day duration starting April 6th begins at 8 am on April 6th and finishes at 8 am on April 10th.

End-of-the-Day (ED) convention

A calendar convention where an activity with a 4-day duration starting April 6th is considered to start at 5 pm on April 5th and finish at 5 pm on April 9th.

$ES_i$ (Early Activity Start)

The earliest possible time that an activity $i$ can begin, determined during the forward pass calculation.

$EF_i$ (Early Activity Finish)

The earliest possible time an activity can be completed, calculated using the formula $EF_{st} = ES_{st} + T_{st}$.

$LF_i$ (Late Activity Finish)

The latest possible time an activity can finish without delaying the project, calculated during the backward pass as $LF_i = \min_{\forall x} (LS_x)$.

$LS_i$ (Late Activity Start)

The latest possible time an activity can start without delaying the project, calculated using the formula $LS_{fi} = LF_{fi} - T_{fi}$.

$T_i$ (Duration)

The total time assigned to complete activity $i$, used in calculations for both early and late start/finish times.

Forward pass calculation

A procedure used to determine early activity times ($ES$ and $EF$) and the overall project duration.

Backward pass calculation

A procedure used to determine late activity times ($LS$ and $LF$) once the project duration is established.

$TF_i$ (Total Float)

The maximum amount of time an activity's completion can be delayed without extending the project completion date; calculated as $TF_i = LF_i - ES_i - T_i$ or $LF_i - EF_i$.

$FF_i$ (Free Float)

The maximum amount of time an activity can be delayed without delaying the early start of any succeeding activities; calculated as $FF_i = (\min_{\forall x} ES_x) - EF_i$.

Lag

The time associated with a link line indicating the difference between the early finish of a preceding activity and the early start of the following activity.

Standard Normal Curve

A distribution curve used in probabilistic methods to consider uncertainties and calculate the probability of an activity (e.g., Masonry or Carpet) finishing within a specific number of days.