ABSTRACT
This chapter focuses on the types of changes made in the maintenance cycle and the reasons for them. As mentioned earlier, users provide a large amount of input concerning program enhancements and additions. Enhancements and additions are a much more desirable form of maintenance because they contain the urgency implied in error correction. Additions and enhancements can be distributed to users in much the same manner as is done for error correction. Just as in error correction, additions and enhancements can be obtained on an exchange basis, where users receive new software by turning in their old versions. As mentioned earlier, the maintenance process is very similar to the structured program design process. These algorithms represent enhancements or additions to the features presently incorporated into the software, and are detailed in the change notice. As the maintenance process continues, new material is added to further document the work that is done.
