A typical engagement always begins with identifying a potential client, winning the engagement, performing the work, and ending with review the project. All of these steps comprise an Engagement Life Cycle. If you have met the client's needs and expectations, the cycle begins again and relationships are strengthened through additional engagements. Please refer to below diagram for a better understanding of the whole lifecycle.

The principal aim of the ICB is to categorize individual companies into subsectors based primarily on a company's "source of revenue or where it constitutes the majority of revenue". If a company is equally divided amongst several distinct subsections, authorities from the Dow Jones and FTSE may be summoned to make a final judgment. Firms may appeal their classification at any time.

The ICB is used globally (though not universally) to divide the market into increasingly specific categories, allowing investors to compare industry trends between well-defined subsectors. The ICB replaced the legacy FTSE and Dow Jones classification systems on 3 January 2006, and is used today by the NASDAQ, NYSE and several other markets around the globe. All ICB sectors are represented on the New York Stock Exchange except Equity Investment Instruments (8980) and Nonequity Investment Instruments (8990).

Note that the terms "industry" and "sector" are reversed from S&P's GICS and the more common usage by professionals.