Chapter 6 project management

CPM enabled project managers to ask what-if questions such as ?

"If the project needs to be finished three weeks early, which activities should be speeded up and how much will it cost?"

Lead

"the amount of time whereby a successor activity can be advanced with respect to a predecessor activity."

Duration is

"the total number of work periods (not including holidays or other nonwork periods) required to complete a schedule activity, usually expressed as workdays or workweeks.

Forward Pass

A critical path method technique for calculating the early start and early finish dates by working forward through the schedule model from the project start date or a given point in time.

Backward Pass

A critical path method technique for calculating the late start and late finish dates by working backward through the schedule model from the project end date.

Successor activity

A dependent activity that logically comes after another activity in a schedule.

Finish-to-finish (FF)

A logical relationship in which a successor activity cannot finish until a predecessor activity has finished.

Start-to-Finish (SF)

A logical relationship in which a successor activity cannot finish until a predecessor activity has started.

Finish-to-Start (FS)

A logical relationship in which a successor activity cannot start until a predecessor activity has finished.

Start-to-Start (SS)

A logical relationship in which a successor activity cannot start until a predecessor activity has started.

Critical Path Method

A method used to estimate the minimum project duration and determine the amount of scheduling flexibility on the logical network paths within the schedule model.

Monte Carlo Simulation

A process which generates hundreds or thousands of probable performance outcomes based on probability distributions for cost and schedule on individual tasks. The outcomes are then used to generate a probability distribution for the project as a whole.

Mandatory Dependency

A relationship that is contractually required or inherent in the nature of the work.

Discretionary Dependency

A relationship that is established based on knowledge of best practices within a particular application area or an aspect of the project where a specific sequence is desired.

Predecessor activity

An activity that logically comes before a dependent activity in a schedule.

Advantages of PERT

Calculations indicate that expected time is actually longer than most likely time

Characteristics of activity

Clear starting and ending points Tangible output that can be verified Scope small enough to understand and control without micromanaging Labor, other costs, and schedule that can be estimated and controlled A single person who can be held accountable for each activity

Advantages of Monte Carlo Simulation

Considers all possible results

PERT

Developed to aid understanding of how variability in the duration of individual activities impacts the entire project schedule

The enumeration method focuses only on one critical path. True or False?

False

Steps to develop project schedule

Identify the critical path Determines the earliest possible end date of the project Methods for determining the critical path

Early Start Date (ES)

In the cirtical path method, the earliest possible point in time when the uncompleted portions of a schedule activity can start based on the schedule newtork logic, the date and any schedule constraints.

Early Finish Date (EF)

In the critical path method, the earliest possible point in time when the uncompleted portions of a schedule activity can finish based on the schedule network logic, the data date, and any schedule constraints.

Late Finish Date (LF)

In the critical path method, the latest possible point in time when the uncompleted portions of a schedule activity can finish based on the schedule network logic, the project completion date, and any schedule constraints.

Late start date (LS)

In the critical path method, the latest possible point in time when the uncompleted portions of a schedule activity can start based on the schedule network logic, the project completion date, and any schedule constraints.

Difficulties of PERT

Infrequently used by project managers

Enumeration

List (enumerate) all paths through the network

Difficulties of PERT

May underestimate the risk of a schedule running long

Difficulties of PERT

No guarantee how good the estimates are

Difficulties of PERT

PMs may informally use 3 time estimates for key activities

Advantages of Monte Carlo Simulation

Provides managers with an intuitive grasp of the project's stand-alone risk

Advantages of Monte Carlo Simulation

Reflects the individual probability distribution of each uncertain input variable, along with the correlations among inputs

Advantages of PERT

Reinforces the degree of uncertainty that exists in project schedules

Disadvantages of Monte Carlo Simulation

Special software and skill required for effective use

Difficulties of PERT

Takes more effort to create 3 estimates

Disadvantages of Monte Carlo Simulation

Time necessary to estimate activity duration and range of outcomes

For each activity, the output to be created and the skill level required to perform the work should be identified. True or False

True

two-pass method

Used to determine the amount of slack each activity has Make two logical passes through the constructed network The forward pass The backward pass

Gantt Chart

a bar chart of schedule information where activities are listed on the vertical axis, dates are shown on the horizontal axis, and activity durations are shown as horizontal bars placed according to start and end dates.

PERT and CPM originally used a method for displaying the work activities called a

activity on arrow (AOA) or arrow diagramming method (ADM), in which schedule activities are represented by arrows and connected at points called nodes

A few major milestones are often identified in the project charter,

but quite commonly more milestones are identified during project schedule planning.

It is a good idea to have someone on your project team play devil's advocate to

challenge the team to identify additional activities. It is better to identify activities that do not need to be accomplished than to forget activities that will need to be added later.

Any time a change to an activity on the critical path happens?

changes the end date of the entire project

All assumptions and constraints made when estimating should be documented since if one of these

changes, can change the estimate.

Leads are helpful if a project needs to be

completed quickly since they show how a successor activity can be overlapped with its predecessor instead of waiting until the predecessor is completely finished.

One common strategy for handling Uncertainty in Project Schedules is to

construct the best schedule possible and then manage the project very closely

The basic Gantt chart does not show

critical path, predecessor-successor relationship, or late start and finish dates

An activity is

distinct scheduled portion of work performed during the course of a project.

The communication plan, requirements traceability matrix, and scope statement are often

either complete or at least in draft form at this point.

The primary advantage of PERT is that it helps everyone realize

how much uncertainty exists in the project schedule

Both CPM and PERT were founded on the concepts still in place today of

identifying activities, determining their logical order, and estimating the duration for each.

When estimating how long activities are expected to take, each activity should be evaluated

independently.

Remember the schedule will not be approved until all of the related planning

is in place. It is better to discover a missing activity in the later stages of planning than after the schedule is approved

A common method of determining this sequence

is to put each defined activity on a Post-it Note and to display them on a large work space

Common milestones include completion of a

major deliverable, completion of a critical activity, and the time just before a large amount of money needs to be committed to the project.

If overtime is planned right from the start, the project manager is unlikely to have

much flexibility if the schedule needs to be accelerated.

Activities should be listed in a

noun-verb format such as prepare budget, build frame, test code &analyze data.

the two-pass and enumeration methods. uses the same activity identification, duration estimate, and activity sequencing data but

processes the data in a different manner

Two project scheduling methods were

program evaluation and review technique (PERT) and critical path method.

PERT

sequences activités to a network

For the first estimate of each activity, a normal level of labor and equipment and a normal work week

should be assumed.

advantage of enumeration method

since all of the paths are identified and timed, if a team needs to compress the project schedule, they will know both the critical path and the other paths that may be nearly critical

lag

the amount of time whereby a successor activity is required to be delayed with respect to a predecessor activity.

Because Identifying the critical path is the longest sequence of activities, the critical path determines

the earliest possible end date of the project

A milestone is an important point in a project schedule that

the project sponsor and manager want to use as a checkpoint.

A project manager and team usually develop as much of the schedule as they can based upon the information in

the work breakdown structure (WBS).

If the project being planned is similar to previous projects, the team can look at

those projects both for defining activities and for other planning that follows

Critical path is important because of

time and everyone wants their projects completed at the promised time

When a past project is being used as a guide, the actual time it took to perform the activities should be used, not the

time that was initially estimated.

On many projects, a great deal of

uncertainty exists, and PERT helps to make this visible.