As an administrator you need things to be as easy as possible so you don’t spend all your time bogged down with issues/complicated settings or even having to modify the source code on a regular basis.

RAD stands for rapid application development. With this methodology you use structured techniques, and prototyping to set your requirements, get prototypes quickly and use minimal planning. It's essentially one process that wraps several stages into one (requirements, design and possibly even the development processes.) It's close to the agile mathod but the main difference is the use of prototyping.