Contrary to what many think, maintenance isn't a one-size-fits-all function; that's why we distinguish between corrective, adaptive, perfective, and preventive maintenance

• Corrective: identify and remove faults in the software.

• Preventive: change software to make it easier to maintain.

• Adaptive: change software so that it functions correctly in a changed environment, such as on a different hardware platform or for use with a different operating system.

We start with corrective, then move to preventive, i.e., refactoring the software and bringing it to a maintainable level. Once that's done, we, along with our client, evaluate both the software and the situation to determine any additional maintenance, or development, needs.