Concept of Project Scheduling - What is the root cause for late delivery of software?

After all the important elements are defined for a project, it is now time to connect all the elements. It means a network of all engineering tasks is created that will enable you to get the job on time. The responsibility for each task is assigned to make sure that it is done and adapt the network. The software project managers does this at the project level and on an individual level, software engineers themselves.

Project scheduling is important because there are many tasks running in parallel in a complex system and the result of each task performed has a very important effect on the work that is performed by other task. These inter-dependencies are very difficult to understand without project scheduling.

The basic reasons why software is delivered late are:
- Unrealistic deadline by someone outside the software group.
- Changing the requirements of customer and not reflecting them in schedule change.
- Underestimate of amount of effort and number of resources required for the job.
- Non considerable predictable or unpredictable risks.
- Technical difficulties that are left unseen.
- Human difficulties that are left unseen.
- Lack of communication or mis-communication among project staff.
- Project management is not able to judge that project is falling behind schedule.

The estimation and scheduling techniques when implemented under constraint of defined deadline gives the best estimate and if this best estimate indicates that the deadline is unrealistic, the project manager should be careful from undue pressure.

If the management demands that the deadline is unrealistic then following steps should be done:
- A detailed estimate is made and and estimated effort and duration is evaluated.
- Develop a software engineering strategy using incremental process model.
- Explain to the customer the reasons why the deadline is unrealistic.
- An incremental development strategy is explained and offered as an alternative.