The next step is to determine, based on the nature of the problem, what type of consultant is needed. An advisory consultant analyzes the problem and turns recommendations over to the client, but is not involved in implementation of the solution. In contrast, an operational consultant remains on hand to assist the client in proper implementation, or in some cases handles the implementation without the client's assistance. Part-time consultants are generally employed full-time within their field of expertise—marketing, for example—but also offer their services to other companies on the side. They usually charge less money than full-time consultants, but they also cannot devote their undivided time and energy to the client.

Process consultants are skills-oriented generalists. With expertise in one or more technical areas, these consultants can apply their skills to any industry or organization. In contrast, functional consultants apply their skills to a particular environment; for example, a hospital facilities planner would concentrate on consulting to hospitals, rather than to other types of businesses that require facilities planning. Another distinction between consultants is based on the size of their operation. Consultants can work for large firms, small firms, or even independently. Large firms offer greater resources, but also have higher overhead and thus charge higher fees. Small firms or independent consultants may offer more attentive service, but may not have access to the precise type of talent that is required. Finally, consultants can be academically or commercially based. In general, academic consultants may be most helpful with problems requiring research or a background in theory, while commercial consultants may be able offer more practical experience.