The functions of consulting services are commonly broken down into eight task categories. Consultants can function as bridges for information and knowledge, and that external consultants can provide these bridging services more economically than client firms themselves. Consultants can be engaged proactively, without significant external enforcement, and reactively, with external pressure. Proactive consultant engagement is engaged mainly with aim to find hidden weak spots and improve performance, while the reactive consultant engagement is mostly aimed at solving problems identified by external stakeholders.