Engineering Tolerance is the amount of variation in a product that will still allow it to function as intended. In the process of developing plans for a product, engineers create certain specifications, which include the amount of variation that will be acceptable. They consider how and where the product will be used, and what kinds of conditions might be present. Their detailed discussions of what the product will do and how also provide information about how close the tolerances need to be. On engineering drawings used in product development, Engineering Tolerance can be indicated.