Cost of Maintenance

Cost of Maintenance:

The cost of system maintenance represents a large proportion of the budget of most organizations that use software systems. More than 65% of software lifecycle cost is expended in the maintenance activities. 

Cost of software maintenance can be controlled by postponing the. development opportunity of software maintenance but this will cause the following intangible cost: 

• Customer dissatisfaction when requests for repair or modification cannot be addressed in a timely manner.
• Reduction in overall software quality as a result of changes that introduce hidden errors in maintained software.

Key Factors affecting Cost are:

1. Non Technical 
2. Technical

Application Domain:

• If the application of the program is defined and well understood, the system requirements may be definitive and maintenance due to changing needs minimized.

Staff Stability:

• It is simple for the original writer of a program to understand and change an application rather than some other person who must understand the program by the study of the reports and code listing.

Program Lifetime:

• Programs become obsolete when the program becomes obsolete, or their original hardware is replaced, and conversion costs exceed rewriting costs.

Dependence on External Environment:

• Changes in a taxation system might need payroll, accounting, and stock control programs to be modified.
• Taxation changes are nearly frequent, and maintenance costs for these programs are associated with the frequency of these changes.

Hardware Stability

• If an application is designed to operate on a specific hardware configuration and that configuration does not change during the program's lifetime, no maintenance costs due to hardware changes will be incurred.
• Hardware developments are so increased that this situation is rare.

 

Module Independence

It should be possible to change one program unit of a system without affecting any other unit.

Programming Language

Programs written in a high-level programming language are generally easier to understand than programs written in a low-level language.

Programming Style

The method in which a program is written contributes to its understandability and hence, the ease with which it can be modified.

Program Validation and Testing:

• Maintenance costs due to bug's correction are governed by the type of fault to be repaired.
• Coding errors are generally relatively cheap to correct, design errors are more expensive as they may include the rewriting of one or more program units.