IT consultants perform a variety of functions, but the major items are implementation of new systems, architecture design, health checks, and knowledge transfer. Some firms offer longer term staffing solutions as well, but that typically isn't pure consulting. Most large firm's IT staff are busy maintaining the systems they already have, and when they want to add a new complex technology they often don't have the time to become an expert on the new stuff and be able to design an architecture and implement it correctly the first time out. Think of it like building a new house: The first time out of going to have some issues because of the learning curve. You want someone who has built that before. That's where consultants come in. A consulting firm would gather the requirements, design the architecture, build a project plan, provide experienced resources, and build the new system.The same consultants often do knowledge transfer as well. The clients IT staff may go to a