CON 101 Chapter 9 (Exam 3)

Network diagrams

A common type of construction schedule, also called the critical path method (CPM), that depicts a continuous chain of activities showing both activity durations and the relationship of the activities. There are two types of network diagrams: activity-on-arrow (AOA) and activity-on-node (AON).

Precedence diagramming

A graphic representation of a schedule depicting project activities on a node with an arrow that depicts the dependencies that exist between the activities.

Forward pass

A scheduling technique used to calculate an activity's early start and early finish. The forward pass must be completed before the project duration can be determined.

Backward pass

A scheduling technique used to calculate an activity's late start and late finish.

The activities that have no total float will be the activities on the critical path.

After you complete a forward and backward pass, how do you know which activities are on the critical path?

Short-interval schedules

Also called look-ahead schedules. They focus on a short period of time and a limited scope of work. They usually plan work for a two to four week time period.

Gantt chart

Considered revolutionary when Henry Gantt first published this planning tool around 1910, a type of bar chart that illustrates a project schedule. It displays the start and finish dates of the various activities of a project.

Production activities (installing siding), procurement activities (ordering windows), and administrative activities (obtaining the building permit).

Name the three different types of activities that are included in the typical schedule, and give an example of each.

Activity-on-arrow method and the activity-on-node method

Name two techniques used to create a diagram.

Float

The amount of leeway available to start or complete an individual schedule activity before it affects the planned project completion.

Critical path

The longest path through a network diagram schedule, which includes those activities that have zero days of float. The critical path determines the overall project duration.

Network logic

The order in which activities are sequenced in the network diagram relative to their interdependent relationships.

Forward pass, backward pass, and the total float calculations.

What are the three scheduling calculations that you must perform in order to determine the project duration and the critical path?

Planning, sequencing, and scheduling stage

What are the three stages of network diagram development?

Gantt chart (or bar chart) and the network diagram

What are the two most common types of schedules used in construction?

Look-ahead schedules are developed by superintendents and trade foreman to coordinate the work and activities over a relatively short period of time, usually two to four week intervals. They are often hand-drawn and are distributed to the specific trades involved.

What is a look-ahead schedule, and how is it used?

Precedence diagram

What is another name for the activity-on-node (AON) network diagram?

Float is the amount of time that an activity's start can be delayed before it impacts the project's planned completion.

What is float, slack, in the schedule?

The critical path is the continuous chain of activities with the longest (combined) overall duration in the network diagram. The critical path is important from a management standpoint because the critical path determines the project duration and any delay in any activity along the critical path results in a delay in the overall project.

What is the critical path, and why is it important from a project management standpoint?