Project Scheduling & Tracking
It is an action that distributes estimated effort across the planned project duration, by
allocating the effort to specific software engineering tasks
Scheduling Principles
Compartmentalization Interdependency Time Allocation Define Responsibilities
Define Outcomes Define Milestones Effort Validation
Unit 3 – Managing Software Projects 1
Scheduling Principles
Compartmentalization
The product and process must be decomposed into a manageable number of activities and tasks
Interdependency
Tasks that can be completed in parallel must be separated from those that must be completed serially
Time Allocation
Every task has start and completion dates that take the task interdependencies into account
Effort Validation
Project manager must ensure that on any given day there are enough staff members assigned to complete
the tasks within the time estimated in the project plan
Define Responsibilities
Every scheduled task needs to be assigned to a specific team member
Define Outcomes
Every task in the schedule needs to have a defined outcome (usually a work product or deliverable)
Defined Milestones
A milestone is accomplished when one or more work products from an engg task have passed quality review
Unit 3 – Managing Software Projects 2
Effort Distribution
General guideline: 40-20-40 rule
40% or more of all effort allocated to analysis and design tasks
20% of effort allocated to programming
40% of effort allocated to testing
Characteristics of each project dictate the distribution of effort
Although most software organizations encounter the following projects types:
Concept Development
▪ initiated to explore new business concept or new application of technology
New Application Development
▪ new product requested by customer
Application Enhancement
▪ major modifications to function, performance or interfaces (observable to user)
Application Maintenance
▪ correcting, adapting or extending existing software (not immediately obvious to user).
Reengineering
▪ rebuilding all (or part) of an existing (legacy) system
Unit 3 – Managing Software Projects 3
Scheduling methods
Two project scheduling methods that can be applied to software development.
Program Evaluation and Review Technique (PERT)
Critical Path Method (CPM)
Both techniques are driven by information already developed in earlier project planning
activities:
estimates of effort
a decomposition of the product function
the selection of the appropriate process model and task set
decomposition of the tasks that are selected
Both PERT and CPM provide quantitative tools that allow you to:
Determine the critical path—the chain of tasks that determines the duration of the project
Establish “most likely” time estimates for individual tasks by applying statistical models
Calculate “boundary times” that define a “time window” for a particular task
Unit 3 – Managing Software Projects 4
Project Schedule Tracking Gantt chart
The project schedule provides a road map for a A Gantt chart, commonly used in project
software project manager. management, is one of the most popular
It defines the tasks and milestones. and useful ways of showing activities
(tasks or events) displayed against time.
Several ways to track a project schedule:
Conducting periodic project status meeting On the left of the chart is a list of the
Evaluating the review results in the software process activities and along the top is a suitable
Determine if formal project milestones have been time scale.
accomplished
Compare actual start date to planned start date for each task
Each activity is represented by a bar;
Informal meeting with practitioners
the position and length of the bar
Using earned value analysis to assess progress
reflects the start date, duration and end
quantitatively
date of the activity. This allows you to
Project manager takes the control of the schedule in see briefly:
the aspects of
Project Staffing, Project Problems, Project Resources,
Reviews, Project Budget
Unit 3 – Managing Software Projects 5
Gantt chart Cont.
What the various
activities are
When each activity
begins and ends
How long each activity
is scheduled to last
Where activities
overlap with other
activities, and by how
much
The start and end date
of the whole project
Unit 3 – Managing Software Projects 6
CPM (Critical Path Method)
Key Points
• What tasks must be carried out.
• Where parallel activity can be performed.
• The shortest time in which you can complete a project.
• Resources needed to execute a project.
• The sequence of activities, scheduling and timings involved.
• Task priorities.
• The most efficient way of shortening time on urgent projects.
Unit 3 – Managing Software Projects 7
CPM (Critical Path Method)
• The critical path is the sequence of activities with the longest duration.
• A delay in any of these activities will result in a delay for the whole project.
Unit 3 – Managing Software Projects 8
CPM (Critical Path Method)
• Float is the amount of time an activity can slip before it causes your project to be delayed.
Float is sometimes referred to as slack.
• Each of the activities on critical path has a float of
zero.
• If any of those activities slips, the project will be
delayed.
• Then take the next longest path. Subtract its duration
from the duration of the critical path. That's the float
for each of the activities on that path.
• Continue doing the same for each subsequent longest
path until each activities float has been determined.
• If an activity is on two paths, it's float will be based on
the longer path that it belongs to.
Unit 3 – Managing Software Projects 9
CPM (Critical Path Method) - Example
Possible paths
Start → A → C → F → Finish: 13
Start → B → D → E → Finish : 09
Start → A → D → E → Finish : 08
Start → B → F → Finish : 09
Critical Path
Unit 3 – Managing Software Projects 10
CPM (Critical Path Method) - Example
Slack = 0
Slack = 0 Slack = 0
EST = 0 EST = 7
EST = 2
EFT = 2 EFT = 13
EFT = 7
LF = 2 LF = 7 LF = 13
LS = 0 LS = 2 LS = 7
Slack = 4 Slack = 4 Slack = 4
EST = 0 EST = 3 EST = 7
EFT = 3 EFT = 7 EFT = 9
11
LF = 7 LF = 11 LF = 13
LS = 4 LS = 7 LS = 11
Unit 3 – Managing Software Projects 11
