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B Naresh Lecturer in Computer Science BVRICEB Naresh Lecturer in Computer Science BVRICE B Naresh Lecturer in Computer Science BVRICEB Naresh Lecturer in Computer Science BVRICE PROJECT SCHEDULEIn project management, a schedule is a listing of a project milestone activities, and deliverables, usually proposed start and finish dates.
In many industries such as engineering and construction the development and maintenance of project schedule is a responsibility of a full time schedule depending on the size of the project.
Terminologies in Project Scheduling
• Milestone: An event to mark specific points in time along a project timeline. These points may signal anchors such as a project start and end date.
• Define Activities – identifying the specific actions to be performed to produce the project deliverables
• Sequencing Activities – identifying and documenting relationships among the project activities.
• Estimate Activity Resources – estimating the type and quantities of material, people, equipment, or supplies required to perform each activity.
• Estimate Activity Duration – approximating the number of work periods needed to complete individual activities with estimated resources.
Technique used for project scheduling Work Breakdown Structure
Dividing complex projects to simpler and manageable tasks is the process identified as WORK BREAKDOWN STRUCTURE (WBS).
Usually, the project managers use this method for simplifying the project execution. In WBS, much larger tasks are broken-down to manageable chunks of work. These chunks can be easily supervised and estimated.
Further sub dividing can be said as Decomposition.
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B Naresh Lecturer in Computer Science BVRICEB Naresh Lecturer in Computer Science BVRICE B Naresh Lecturer in Computer Science BVRICEB Naresh Lecturer in Computer Science BVRICE EXAMPLE ON WBSAim of Work Breakdown Structure
Giving visibility to important work efforts.
Giving visibility to risky work efforts.
Illustrate the correlation between the activities and deliverables.
Show clear ownership by task leaders.
****************************************************************************** Project Scheduling Tools OR Techniques
MOSTLY COMMONLY USED METHODS ARE:
1. Gantt chart
2. Network diagrams(PERT/CPM)
Gantt chart
A Gantt chart, commonly used in project management, is one of the most popular and useful ways of showing activities (tasks or events) 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 allows you to see at a glance:
What the various activities are
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B Naresh Lecturer in Computer Science BVRICEB Naresh Lecturer in Computer Science BVRICE B Naresh Lecturer in Computer Science BVRICEB Naresh Lecturer in Computer Science BVRICE How long each activity is scheduled to lastWhere activities overlap with other activities, and by how much
The start and end date of the whole project
To summarize, a Gantt chart shows you what has to be done (the activities) and when (the schedule).
A simple Gantt chart
Uses
◦ Easy to read
◦ Give each team members overview of the project. ◦ Indicate clearly the status of each activity
◦ Can be drawn to show the budgets, equipment's usage
****************************************************************************** NETWORK DIAGRAMS (PERT/CPM)
The PERT/CPM Procedure
There are six stages common to both PERT and CPM:
1. Define the project and specify all activities or tasks.
2. Develop the relationships amongst activities. Decide upon precedence’s.
3. Draw network to connect all activities.
4. Assign time and/or costs to each activity.
5. Calculate the longest time path through the network: this is the "critical path".
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B Naresh Lecturer in Computer Science BVRICEB Naresh Lecturer in Computer Science BVRICE B Naresh Lecturer in Computer Science BVRICEB Naresh Lecturer in Computer Science BVRICE Analysis of the project normally involves:1. Determining the Critical Path. The critical path is the group of activities in the project that have a slack time of zero. This path of activities is critical because a delay in any activity along it would delay the project as a whole.
2. Calculating the total project completion time, T. This is done by adding the activity times of those activities on the critical path.
Critical Path Analysis
The objective of critical path analysis is to determine times for the following:
• ES = Earliest Start Time. This is the earliest time an activity can be started, allowing for the fact that all preceding activities have been completed.
• LS = Latest Start Time. This is the latest time an activity can be started without delaying the start of following activities which would put the entire project behind schedule.
• EF = Earliest Finish Time. The earliest time an activity can be finished.
• LF = Latest Finish Time. The latest time that an activity can finish for the project to remain on schedule.
• S = Activity Slack Time. The amount of slippage in activity start or duration time which can be tolerated without delaying the project as a whole.
If ES and LS for any activity is known, then one can calculate values for the other three times as follows:
EF = ES + t
LF = LS + t
S = LS - ES or S = LF - EF
The steps in critical path analysis are as follows:
a) Determine ES and EF values for all activities in the project: the Forward Pass through the network.
b) Calculate LS and LF values for all activities by conducting a Backward Pass through the network.
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B Naresh Lecturer in Computer Science BVRICEB Naresh Lecturer in Computer Science BVRICE B Naresh Lecturer in Computer Science BVRICEB Naresh Lecturer in Computer Science BVRICE d) Calculate total project completion time.PERT and Activity Time Estimation
The major distinguishing difference between PERT and CPM is the use of three time estimates for each activity in the PERT technique, with CPM using only one time for each activity using CPM.
The three time estimates specified for each activity in PERT are:
i) the optimistic time;
ii) the most probable time; and
iii) the pessimistic time.
• Optimistic time (O): the minimum possible time required to accomplish a task, assuming everything proceeds better than is normally expected
• Pessimistic time (P): the maximum possible time required to accomplish a task, assuming everything goes wrong.
• Most likely time (M): the best estimate of the time required to accomplish a task, assuming everything proceeds as normal.
The formulae used are as follows:
Where:
o, m, p - optimistic, most likely, and pessimistic times
t - Expected completion time for task
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B Naresh Lecturer in Computer Science BVRICEB Naresh Lecturer in Computer Science BVRICE B Naresh Lecturer in Computer Science BVRICEB Naresh Lecturer in Computer Science BVRICE Process and Project MetricsMetrics provide the scale for quantifying qualities. For example, in software project the length is seen in terms of size metric of Software, then the unit of measurement of size is LOC (Line of Code).
Types of Metrics:
Indirect Metric: If metric can‟t be measured directly eg: Reliability of the software, that is estimated from other possible measurements.
Direct Metric: Metric that can be measured directly eg: Size
One way of Categorization of Software Metric:
Process Metrics
Process metrics are used to check the progress of project development. These metrics leads to Software process improvement.
The steps of the software process improvement are as follows:
1- Specific attributes of process are measured
2- This results in the development of various metrics 3- Execution of these metrics will provide indicators 4- These indicators will improve the process
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B Naresh Lecturer in Computer Science BVRICEB Naresh Lecturer in Computer Science BVRICE B Naresh Lecturer in Computer Science BVRICEB Naresh Lecturer in Computer Science BVRICE Project metricProject metrics are used by the project manager and a software team to check the project progress and the activities related to the project. Data from past projects are used to collect the various metrics (Time and Cost) then these metric and their estimates act as the base of the new software. As the project proceeds, the project manager will check its progress regularly time to time and compare the effort, time cost, with the estimated ones.
Project Metrics or indicator enables a software project manager to. Assess the status of an ongoing project
Track potential risks.
Uncover problem areas before they go “Critical” Adjust work flow or tasks
Evaluate the project team’s ability to control quality of software work products.
