How to develop information systems that are easy to maintain

Introduction :

Maintenance is a basic requirement that takes around 60% of the time sometimes unnecessary time is taken up by maintenance which is totally a waste because with little more planning or testing this could be avoided. Louis A Rose has once stated: “I firmly believe that the maintenance of a system is a direct function of how well it was developed initially”.

Now we will discuss certain factors that should be kept in mind while developing a system so that the maintenance time can be minimized. Here are the factors are given below as follows.

1. With the eye of the future, the systems should be planned.
2. The specification of the user should be correct.
3. A modular system is required.
4. Complete all the documentation.
5. During development, standards should be followed.
6. Testing Should be thorough.
7. For the development cycle, adequate time should be allowed.
8. Human factors should be considered and attention should be paid to end-users and ergonomics(health conditions).
9. With the relationship between system design and system maintenance, the development team should be fully aware.

For users and maintenance is important for documentation so far we have seen this and the importance of maintenance for the smooth functioning of systems. For communication, the documentation is very important and necessary too from the development team to all potential users. The documentation proves very useful if emergency maintenance is needed only if there is an absence of the members of the development team, also since all the facts, there is a record for all the assumptions future maintenance becomes very easy by this. For easy, error-free functioning maintenance is necessary for the system and also for keeping abreast with changing requirements and changing technologies. So the documentation which we are discussing and the other factor maintenance are unpopular but very important aspects of software development.

Points related to programming methodology :

• For a good program, meaningful names for identifiers should be used.
• Expressions should be simple and clear.
• For enhancing the readability the comments and identification should be used.
• To make the program more readable blank lines and spaces should be inserted.
• Robust should be made by a program. Robustness means the ability of a program to recover following an error and to continue operating within its environment.
• Errors that violate the grammatical rules and regulation of programming language are under the compile-time errors (syntax error and semantics errors).
• During the execution of a program, run-time errors occur.
• Due to mistaken analysis of the problem logical errors occur.

CASE STUDY :

Survey Finds Maintenance Problem Severe :

By the release of Quality Assurance Institute survey results in 1986 within large data centers the software maintenance problem has yet to be solved. The highlights of the survey are here which polled 37 Fortune 500-class companies.

• From two months to 60 months- the average was 23 months through the maintenance backlogs in the companies surveyed range is this.
• Expenditure of maintenance ranged from 10 percent to 90 percent of data processing budgets- the average was 51 percent.
• Nearly 80 percent of the respondents had systems whose logic could only be understood by specific individuals. This prevented rotating maintenance responsibility among data processing personnel.
• Formal methods for deciding when to rewrite programs existed in less than 15 percent of the companies surveyed. The requirement that older systems conform to the same programming standards as a newly developed system, was found in 16 percent of the firms.
• In all but 5 percent of the firms surveyed, it was acknowledged that a programmer working on new systems’ development had a more prestigious position than one assigned to maintenance.