Ch. 19 (OM)

Critical activities have a slack of . . .

0 (zero)

Gantt Chart

A chart on which project tasks or events are displayed against time. On the left of the chart is a list of the activities and along the top is a suitable time scale. Each activity is represented by a bar; the position and length of the bar reflects the start date, duration and end date of the activity. This lets you see: What the activities are When each activity begins and ends How long each activity is Where activities may overlap The start and end date of the project Henry Gantt

Project

A temporary (and thus nonrepetitive) operation. Have a limited time frame with defined beginning and end, one or more specific objectives, and a temporary organizational structure, and thus often are operated in a more ad-hoc, improvised management style. ex) a major event like a wedding, any construction project, designing a political campaign, an audit

Crashing Projects

Accelerating a project by committing more resources than initially planned.

Which of the following statements is correct with respect to a Gantt chart? - The x-axis of a Gantt chart shows a time line - The y-axis shows the activities of a project - The Gantt chart itself does not show all dependencies among activities - The Gantt chart is named after 19th century industrialist Henry Gantt - All of these statements are correct

All of these statements are correct

Which of the following statements is correct with respect to slack time? - The slack time of an activity is the latest completion time of the activity minus the earliest completion time - The slack time of an activity is the latest start time of the activity minus the earliest start time - The slack time of an activity determines by how much an activity can be delayed without impacting the overall completion of the project - All of these statements are correct

All of these statements are correct

Which statement is true? - Both PERT and CPM use activity networks in their analysis. - PERT cannot give an estimate of the project completion time - CPM is preferred when activity times are uncertain (probabilistic.) - Only CPM gives an estimate of the slack for non-critical activities.

Both PERT and CPM use activity networks in their analysis.

Project Scope

Description of what must be accomplished in order for the project to be complete.

T/F: In an AON graph of a project, there only exists one path from the first to the last activity.

False

T/F: The work crew to install windows cannot arrive until Day 17. The house cannot be completed on time.

False

T/F: The activity with the lowest crash cost per unit time should be crashed first.

False, the critical activity with the lowest crash cost should be crashed first.

Using PERT

Finding the critical path : Use CPM with the mean activity times. Obtain the expected project completion time. The overall project completion time is assumed to have a normal distribution with mean equal to the sum of the means along the critical path, and variance equal to the sum of the variances along the critical path.

three-time estimate approach for uncertain activity time

For each activity, estimate the following times: a = the optimistic time (min duration) b = the pessimistic time (max duration) m = the most likely time (normal duration)

Both PERT and CPM do what?

Graphically display the precedence relationships & sequence of activities on an activity network Estimate the project's durationIdentify critical activities that cannot be delayed without delaying the project Estimate the amount of slack associated with non-critical activities

Principal methods for crashing

Improving existing resources productivity, changing work methods, increasing the quantity of resources

Which of the following statements are correct with respect to an AON graph of a project? - In an AON graph, the activities are on the edges of a graph - In an AON graph, the activities are on the nodes of a graph - AON stands for the American Operations Norm - None of these statements are correct.radio button unchecked

In an AON graph, the activities are on the nodes of a graph

A project has four activities that take 4, 3, 6, and 7 days respectively. What is the total completion time for the project? - 3 days, as this is the minimum time - 7 days, as this is the maximum time - 20 days, as this is the sum of the times - It is not possible to determine the total completion time from the given information

It is not possible to determine the total completion time from the given information Depends on the precedence relationships between the activities.

Project Budget

Outline of the main expenses associated with the project.

Which statement is true? - PERT assumes that the activity time for each activity is dependent on another activity - PERT uses a normal distribution to calculate the mean and variance for each activity - PERT assumes that the project completion time is normally distributed - All of the above are false

PERT assumes that the project completion time is normally distributed

Project Cost

Planning for time and money.

Activity Time

The amount of time it takes a resource to complete the activity once it has started to work on it. The concept is the same as the processing time in a process analysis.

Earliest Start Time (EST)

The earliest time an activity can begin, which is given by the earliest time all predecessor activities have been completed

Consider two projects that have the same activities and the same dependencies. In the first project, the activity times are expected outcomes. The actual times will vary. In the second project, the activity times are always as expected. On average (in expectation), which project will be completed first?

The first

Project Management Triangle

The tension between the three objectives of a project: time, budget, and scope.

T/F: PERT assumes that non-critical activities will never become critical.

True

What is often displayed on the Gannt Chart?

additional information about the tasks or phases of the project, how far each project has progressed, what resources are being used for each tasks, etc. .

Activities on the ______ ______ must be started and completed on time or the project is delayed

critical path

Any path going from the start to the finish with slacks of 0 is a . . .

critical path

PERT is considered probabilistic and CPM is considered . . .

deterministic.

Project completion times may need to be shortened because . . .

different deadlines, penalty clauses, need to put resources on a new project, promised completion dates

PERT builds on the CPM to calculate the . . .

expected project completion time

Projects have a . . .

limited time frame, one or more specific objectives, and a temporary organizational structure, and are operated in a more ad-hoc, improvised management style.

The project completion time is the ______ of the ECT.

maximum

The critical path in a project is the sequence of activities that: - has the shortest time - has the smallest number of activities - has the shortest budget - none are correct

none are correct `

Network diagrams and Gantt charts are used to . . .

organize projects and track their progress

A project network can be constructed to model the . . .

precedence of the activities. The nodes of the network represent the activities The arcs of the network reflect the precedence relationships of the activities.

Crashing activities that are not on the critical path typically do not . . .

reduce project completion time

Projects have all of the following characteristics except: - temporary - set beginning and end - repetitive - projects have all

repetitive

The standard deviation for a PERT diagram is calculated by:

taking the sum of the variances of the nodes on the critical path and then find the square root of that sum

slack time

the amount of time an activity can be delayed without affecting the overall completion time of the project

To reduce the length of the project (crashing), we need to know . . .

the critical path of the project and the cost of reducing individual activity times

The Gannt Chart is useful for identifying . . .

the critical path, important deficiencies, slack time

Precedence Relationship

the dependency of activities on each other

Earliest Completion Time (ECT)

the earliest time an activity can be completed, which is given by the earliest time all predecessor activities have been completed plus the activity time

latest start time (LST)

the latest possible start time of an activity that still allows for an on-time completion of the overall project Potentially delay the start of the activity Accommodate the availability of resources Insights and understanding about project dynamics

late start schedule

the latest possible timing of all activities that still allows for an on-time completion of the overall project

Program Evaluation and Review Technique (PERT) is used to calculate . . .

the probability a project will be completed on time.

Cease crashing when . . .

the target completion time is reached, the crash cost exceeds the penalty cost

The Critical Path Method identifies . . .

the tasks that are critical for the on-time completion of a project.

The key objectives of a project are given by:

time, scope, budget

For new or unique projects, such as new product development or movie production, activity times will be . . .

uncertain We may deal with this by representing each activity duration by a random variable and assuming a probability distribution for it.

Projects are temporary operations resulting in a . . .

unique outcome