Check Sheets are means of tallying data. They generally are kept at the point of data collection, and every time a particular incident happens, a check is placed in the appropriate box.
In many cases, the check sheet will be broken down into a grid. The columns most often contain the different types of occurrences. The rows are broken down into time periods, whether hours, days, or a longer period.
Whenever an event occurs, such as a customer complaint, or a defective part, the person responsible for collecting data places a check in the appropriate column at the appropriate time.
The check sheet is a data collection tool. By the time you are using one, you have likely already started a problem solving process. The check sheet is most often used to help identify the frequency of particular problems to be able to apply the Pareto principle to the solution.
As a variation of the check sheet, record a number instead of a simple check mark. Approximate the time or cost related to the problem and record it in the appropriate box. While it takes a bit more time to record, it provides additional information that can provide better insight into solutions.