Project Scheduling

Project Project ManagementManagement

Project ManagementProject Management

The on-going process of directing and coordinating all the steps in the development of an information system

Goal to produce an IS that is acceptable to its end-user

developed within the specified time frame and budget

Project Management...Project Management...

Rolerecognize such factors and to eliminate/minimize their negative effects

Playersmanages a project to develop an ISdefines a project’s activities and events

estimates the time and cost necessary to complete each activity

Project Management...Project Management...

Players (cont...)schedules and assigns the activities to specific members of the project team

coordinates activitiesmonitors eventsevaluates and reports on the progress of the activities and events

Project SchedulingProject Scheduling

determining the order in which activities will be performed, setting start and end times for each activity, and assigning specific tasks to team members

SCHEDULING TOOLS◦GANTT Charts◦PERT/ CPM Charts

GANTT ChartsGANTT Charts

GANTT Charts◦developed by Henry L. Gantt ◦a horizontal bar that graphically illustrates a

schedule◦horizontal axis : time◦vertical axis : activity◦length of the bar indicates duration of the

activity

GANTT Charts...GANTT Charts...

GANTT Charts (cont...)◦positioning of the bar shows the start and end

of the activity◦useful for tracking and reporting progress◦graphically displays a schedule◦often used to report progress because they

present an easily understood picture of project status


1. The completed portion of each bar is shaded.


current date

2. A triangle or arrowhead indicator is used.


3. A second bar shows the completed work.


Problems◦no indication of activity dependencies◦how an activity which is behind schedule can

influence the entire project◦no. of hours per day required to complete an

activity is not shown◦no. of people assigned is also not shown◦it can not determine how far ahead/behind

schedule a project is

Create a Gantt Chart◦Task 1 – Jan. 14 – Feb 10◦Task 2 – Feb 19 – Mar 18◦Task 3 – Mar 16 – Apr. 24◦Task 4 – May 4 – May 31◦Task 5 – Mar 19 – Apr 14◦Task 6 – Apr 16 – Jun 6◦ Task 7 – May 16 – July 14

PERT/ CPM ChartsPERT/ CPM Charts

PERT (Program Evaluation Review Technique)◦developed by the Navy Special Projects Office

in 1950’s to control the development of the Polaris submarine missile program(Three point estimate)

CPM (Critical Path Method)◦developed by the private industry at the same

time as PERT to meet similar project management needs (Single point estimate)

PERT/ CPM Charts...PERT/ CPM Charts...

Charting Conventions◦Activity

- Describes each task Shown as vectors -Line with an Event Represented as branches (lines)

-Identified by letters

- Start/end of an activity


Event◦displayed graphically as nodes, circle or

rectangle◦identified as node in the network

Path◦sequence of activities leading from the

beginning node to the final node


Dummy Activities◦indicated by dotted lines◦no labeled process description/time◦used to ensure continuity

Simultaneous activity◦serial arrangement means one after the other◦parallel format shows overlapping activities

PERT/ CPM Charts...PERT/ CPM Charts...Concepts:

◦Optimistic time estimate – completion time expected if everything went exactly as planned

◦Pessimistic time estimate – completion time expected if everything possible went wrong

◦Most likely time estimate – only if normal problems are encountered

◦Critical Path – defines the most sensitive part of the chart that may affect the schedule of the whole project (longest time to complete)

◦Slack – extra time to do an activity without affecting project schedules

Getting the Estimated Time and Slack

ET = Optimistic + 4 x Most Likely + Pessimistic / 6

Slack/Float = Earliest Finish – Latest Finish


Rules in PERT/CPM NetworksEach activity must be represented by its

own branch on the chart.Direction of time flows is indicated by

arrows. An activity line meeting an event node indicates activity completion. The length of an activity branch is not representative of the time the activity will take.


Relationship between activities are determined by the sequence of the branches.

If several activities terminate at one node, no activities starting at that node may begin until all entering activities are completed.

For analysis reason, no two activities are allowed to both start and end at the same nodes. If the project network would seem to require this, a dummy activity must be inserted.

A dummy activity has no time, it merely preserves the proper sequencing in the network design.


Steps included:1. determine the activities needed to

complete the project 2. sequential relationship of these activities

(try to establish as many simultaneous activities as possible

3. estimate the completion time for each activity

4. draw the PERT/CPM network, showing the relationship activities as determined in STEP 2


Steps included:5. starting with the beginning node of the

network, use the earliest start – earliest finish relationships to determine the project completion time (Forward Pass)

6. moving to the end node of the network, use the latest start – latest finish relationships to determine the activities on the critical path and the float for activities not on the critical path


7. use the earliest time - earliest finish relationships in STEP 5 and the latest start – latest finish relationships in STEP 6 to develop an activity time table for the project

Network Diagram The most common information shown is:The activity name The normal duration time The early start time (ES) The early finish time (EF) The late start time (LS) The late finish time (LF) The slack

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Project Scheduling