Often this is because developers don’t know the kind of documentation necessary to maintain a system.

Unfortunately, too many systems are delivered with missing or inadequate documentation. System maintainability starts with the ability to understand the existing system and part of understanding the system is a proper set of documentation. The reason for the difficulty in maintaining systems can be broken down into three key areas. The testing process, which removes bugs may not necessarily improve the ability to find bugs, accept configuration changes, or make enhancements. The additional difficulty in maintaining the software far outstrips any benefit that is gained by negotiating with vendors, maintaining tight schedules, or any of the other project management techniques that are typically used to control project costs. The problem with software is that some systems are infinitely more difficult to maintain than others. Subtle differences in the code can make these parts of the software lifecycle painful or relatively pain free. Most of the time and effort is spent supporting, maintaining, and enhancing the system. We are all aware that most of the time and effort spent on a software development effort is not spent within the design and construction phases. While there are still far too many software development projects that don’t meet these metrics there are other less visible factors to the long-term success of the project. All are measured, of course, against the project scope document created at the start of the project or at least measured against the expectation that was set when the project was started. Traditional metrics for the development of a software project watch cost, defect rates, and schedule.

Tor project hopes replace fragile code