Consulting firms consist of individuals specializing in particular business areas, such as by job function (e.g., human resource management), business need (e.g., strategy development), or industry (e.g., transportation). In addition to working for individual clients, consulting firms also produce reports covering their specialties that are made available to the general public. By and large, the bigger the consulting firm the more valid and reliable are the reports they produce.
One group of companies to consider as a starting point is large accounting firms. Nearly all the major accounting firms now have divisions focused on management consulting. These divisions regularly make available industry reports.