lecture 61 project planning tool lecture 62 objectives understand the reasons why projects sometimes...
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Lecture 6 1
Project planning tool
Lecture 6 2
Objectives
Understand the reasons why projects sometimes fail
Describe the different scheduling tools, including Gantt charts and PERT/CPM charts
Calculate completion times, start dates, and end dates for a project
Lecture 6 3
Keys to Project Success
Successful systems must satisfy business requirements, meet users’ needs, stay within budget, and be completed on time
The essential objective is to provide a solution to a business problem
Lecture 6 4
Keys to Project SuccessSome reasons for failure
– Unclear requirements, targets, or scope– Shortcuts or sloppy work– Poor design choices– Insufficient testing or test procedures– Lack of software change control– Changes in culture, funding, or objectives– Unrealistic cost estimates– Poor monitoring and control of progress– Inadequate reaction to early signs of problems– Failure to recognize activity dependencies– Personality conflicts and employee turnover
Lecture 6 5
Project Planning
A project plan is an overall framework for managing costs and schedules
The planning process involves– Activities (tasks)– Events (milestones)
Lecture 6 6 Package
Project Planning
An activity, or task, is a basic unit of work that is planned, monitored, and tracked
An event, or milestone, is a reference point that is used to manage the project
Every activity has two events — one marks the start of the task, the other marks the end
Events must be easily recognizable
Click to see FigureClick to see Figure
Lecture 6 7
Project Scheduling
The project manager must know– The duration of each task– The order in which the tasks will be
performed– The start and end times for each activity– Who will be assigned to each task
Assignments should not overload or under-utilize team members
A level workload is desirable
Lecture 6 8
Scheduling Tools
A project manager can use several graphical planning tools– Gantt charts– PERT/CPM charts
Lecture 6 9
Scheduling Tools
Gantt charts– A Gantt chart is a horizontal bar chart that
illustrates a schedule– Time is shown on the horizontal axis and
activities are arranged vertically– The position of a bar shows the start and end
of a task, and the length of the bar shows the task’s duration
PackageClick to see FigureClick to see Figure
Lecture 6 10
Scheduling Tools
Gantt charts– Tasks can be combined into activity groups to
simplify the chart– Various methods exist for tracking progress
• Shade the completed portion of a bar
• Use a triangle or arrowhead as an indicator
• Use a second bar to show the completed work
PackageClick to see FigureClick to see Figure
Lecture 6 11
Scheduling Tools
PERT/CPM– The Program Evaluation Review Technique
(PERT) and the Critical Path Method (CPM) were developed separately but now are referred to as PERT/CPM
– A PERT/CPM chart displays a project as a network diagram, with activities shown as vectors, and events represented by nodes
Click to see FigureClick to see Figure包裝
Lecture 6 12
Scheduling Tools
PERT/CPM charting conventions– The vectors representing tasks connect the
nodes, which indicate milestones– The activity’s estimated duration is shown
below the vector
PackageClick to see FigureClick to see Figure
Lecture 6 13
Scheduling Tools
PERT/CPM charting conventions– The vectors representing tasks connect the
nodes, which indicate milestones– The activity’s estimated duration is shown
below the vector– Tasks that must be completed in a specific
sequence are called dependent, or serial, tasks
PackageClick to see FigureClick to see Figure
Lecture 6 14
Scheduling Tools
PERT/CPM charting conventions– The vectors representing tasks connect the
nodes, which indicate milestones– The activity’s estimated duration is shown
below the vector– Tasks that must be completed in a specific
sequence are called dependent, or serial, tasks– Dummy activities can be used to show task
dependencies
PackageClick to see FigureClick to see Figure
Lecture 6 15
Scheduling Tools
PERT/CPM charting conventions– A project can be represented with a Gantt
chart and a PERT/CPM chart– Significant differences exist between the two
methods, and each method has strengths and weaknesses
PackageClick to see FigureClick to see Figure
Lecture 6 16
Scheduling Tools
Activity duration– A weighted formula can be used to estimate
activity duration– The formula calculates a weighted result
based on three separate estimates (optimistic (O), pessimistic (P), and most likely (M))
Lecture 6 17
Earliest completion times– The earliest completion time for an activity is
called the ECT– The ECT is the minimum amount of time
needed to complete all the activities that precede the event
PackageClick to see FigureClick to see Figure
Scheduling Tools
Lecture 6 18
Earliest completion times– Working from left to right on the chart, the
ECT is calculated by taking the ECT of the preceding event and adding the duration of the immediately preceding task
– If the event has more than one preceding task, use the largest ECT of the preceding tasks, including any dummy tasks
– The ECT is shown as a number in the upper-right section of the event node symbol
PackageClick to see FigureClick to see Figure
Scheduling Tools
Lecture 6 19
Latest completion times– The latest completion time for an activity is
called the LCT– The LCT is the latest time at which the event
can occur without delaying the overall project
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Scheduling Tools
Lecture 6 20
Latest completion times– To determine an LCT, you reverse the
procedure for an ECT– Work from right to left, and subtract the LCT
of the following task– If the event has more than one following task,
use the smallest LCT of the following tasks, including any dummy tasks
– The LCT is shown as a number in the lower-right section of the event node symbol
PackageClick to see FigureClick to see Figure
Scheduling Tools
Lecture 6 21
Slack times– The slack time for an event is the amount of
time by which an event can be late without delaying the project
– The slack time is the difference between the LCT and the ECT, if any
PackageClick to see FigureClick to see Figure
Scheduling Tools
Lecture 6 22
Critical path– A critical path is a series of events and
activities with no slack time– At least one complete path will exist where
every node has equal ECTs and LCTs– If any task on the critical path is delayed
beyond its LCT, the entire project falls behind by that amount of time
– Project managers focus on the critical path in order to keep the project on track
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Scheduling Tools
Lecture 6 23
Comparing Gantt charts and PERT/CPM– PERT/CPM charts show all task
dependencies, and are better for scheduling, monitoring, and controlling projects
– Gantt charts graphically display the timing and duration of activities, and can display task completion status effectively
– PERT/CPM charts are more complicated than Gantt charts, especially for larger projects
Scheduling Tools
Lecture 6 24
End of Lecture 6