Ans. Problems During Maintenance The most important problem during maintenance is that before correcting or modifying a program, the programmer must first understand it. Then, the programmer must understand the impact of the intended change. Few problems are discussed below. Often the program is written by another person or group of persons working over the years in isolation from each other. Often the program is changed by person who did not understand it clearly, resulting in a deterioration of the program’s original organization. Program listing, even those that are well organized, are not structured to support reading or comprehension. We normally read article or book straight through, but with listing, programmer rummages back and forth. There is a high staff turnover within information Technology industry. Due to this many systems are maintained by persons who are not the original authors. These persons may not have adequate knowledge about the system. This may mean that these persons may introduce changes to programs without being aware of their effects on other parts of the system -the ripple effect. This problem may be worsened by the absence of documentation. Even where it exists, it may be out of date or inadequate. Some problems only become clearer when a system is in use. Many users know that they want but lack the ability to express it in a form understandable to programmers/analysts. This is primarily due to information gap. Systems are not designed for change. If there is hardly any scope for change, maintenance will be very difficult. Therefore approach of development should be the production of maintainable software.