How does this relate to other impact measurement systems
In general, the B Impact Assessment provides a judgment (via an objective, comprehensive rating) on how significant a company’s current impact is. The B Impact Assessment is commonly confused with reporting systems or definition frameworks that detail how a company should go about collecting that impact data, but not necessarily provide a judgment on how significant that company’s impact is.
For example, the Global Reporting Initiative (GRI) or IRIS are platforms that are likely to define specific way to report impact metrics; As an example, they may define how to best report a company's carbon emissions, so that all carbon reports in the future can be easily comparable to each other (ie. Company X is responsible for producing 30,000lbs of carbon, based on its direct emissions from its plant and its electricity purchases). IRIS and GRI definitions and reporting standards are a critical part of the B Impact Assessment.
As a result, a GRI or IRIS indicator is more likely to tell you that the company is reporting its emissions according to best practice. On the other hand, the B Impact Assessment aims to evaluate whether the company has either increased or decreased its emissions relative to the company’s revenues or relative to the practices of other businesses, because this disctinction helps a growing number of consumers, investors, and institutions who want to support businesses who put their values into action.
The B Impact Assessment simply builds upon the important work that other organizations and industry groups are doing to define and measure impact.