Subject: Software Engineering

Topic: Software project scheduling

Difficulty: Medium

Project Scheduling :-

•Project scheduling is an activity that distributes estimated effort across the planned project duration by allocating the effort to specific software engineering tasks.

•One view is that the end-date for the software release is set externally and that the software organization is constrained to distribute effort in the prescribed time frame.

•Another view is that the rough chronological bounds have been discussed by the developers and customers, but the end-date is best set by the developer after carefully considering how to best use the resources needed to meet the customer’s needs.

Software Project 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 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 completed the tasks within the time estimated in the project plan.

• Defined Responsibilities - every scheduled task needs to be assigned to a specific team member.

• Defined milestones - a milestone is accomplished when one or more work products from an engineering task have passed quality review.

Relationship Between People and Effort:-

• Adding people to a project after it is behind schedule often causes the schedule to slip further.

• The relationship between the number of people on a project and overall productivity is not linear (e.g. 3 people do not produce 3 times the work of 1 person, if the people have to work in cooperation with one another) .

• The main reasons for using more than 1 person on a project are to get the job done more rapidly and to improve software quality.

Project Effort Distribution:-

• The 40-20-40 rule:

o 40% front-end analysis and design

o 20% coding

o 40% back-end testing

• Generally accepted guidelines are: o 02-03 % planning

o 10-25 % requirements analysis

o 20-25 % design

o 15-20 % coding

o 30-40 % testing and debugging

Software Project Types:-

1. Concept development - initiated to explore new business concept or new application of technology.

2. New application development - new product requested by customer.

3. Application enhancement - major modifications to function, performance, or interfaces (observable to user).

4. Application maintenance - correcting, adapting, or extending existing software (not immediately obvious to user).

Factors Affecting Task Set:-

• Size of project

• Number of potential users

• Mission criticality

• Requirement stability

• Ease of customer/developer communication

• Maturity of applicable technology

• Performance constraints

Concept Development Tasks:-

• Concept scoping - determine overall project scope.

• Preliminary concept planning - establishes development team's ability to undertake the proposed work.

• Technology risk assessment - evaluates the risk associated with the technology implied by the software scope.

Scheduling:-

• Task networks (activity networks) are graphic representations can be of the task interdependencies and can help define a rough schedule for particular project.

• Scheduling tools should be used to schedule any non-trivial project.

• Program evaluation and review technique (PERT) and critical path method (CPM) ) are quantitative techniques that allow software planners to identify the chain of dependent tasks in the project work breakdown structure (WBS) that determine the project duration time.

Tracking Project Schedules:-

• Periodic project status meetings with each team member reporting progress and problems.

• Evaluation of results of all work product reviews.

• Comparing actual milestone completion dates to scheduled dates.

Tracking Increment Progress for OO Projects:-

• Technical milestone: OO analysis complete

o All hierarchy classes defined and reviewed

o Class attributes and operations are defined and reviewed

o Class relationships defined and reviewed