Check Sheet

A check sheet is one of the 7 basic tools of quality used for manufacturing processes. It tracks data much like a kanban board. It can be qualitative or quantitative, and the latter is also known as a tally sheet.

What Is A Check Sheet?

A check sheet is a type of organized chart or list that can help track the progress of assigned tasks. It was identified by postwar organizational engineer Kaoru Ishikawa as one of the 7 Basic Tools of Quality used in manufacturing.

A check sheet is frequently used to answer the 5 Whys. In other words, the check sheet identifies:

• WHO filled it out
• WHAT data was collected
• WHERE it was collected
• WHEN it was collected
• WHY the data was collected

These data categories are necessary to analyze process improvements and workflow, as well as avoid defects and fix production errors.

Purpose of a Check Sheet

A check sheet is a visual indicator of data collected while a process unfolds. It can be as simple as a numbered checklist to be followed sequentially, or as complicated as the task requires.

It operates much like a kanban board, which is a visual display of jobs currently in progress or work to be done. It differs from a kanban board in that it tracks a single job’s progression as well as information about the workers, specs, and location of the job.

5 Types of Check Sheets

There are many different types of check sheets, and this list is not exhaustive because different project managers can tweak the details of check sheets to suit their custom needs. Regardless, the following 5 examples are the most common types of check sheets used.

Quantify defects by type

Defects can range from many issues, and vary from chips, bubbles, cracks, size abnormalities, and so on. Therefore, this type of check sheet is used to evaluate which types of defects are more frequently occurring than others. This shines a light on bottlenecks and areas of further improvement.

The data from this type of check sheet should be assembled in a final pareto chart. That way, it is easy to see which defect type should be addressed first, because it is more frequent than the others.

Verify shape of probability distribution

This type of check sheet is perhaps the more complicated of the types because it is intertwined with another of the 7 basic tools of quality: the histogram.

A histogram is used to see probability distribution. It’s like a bar chart, but instead of each bar representing a value, each bar is a “bin” that holds values within a specific range. For example, a bar chart would plot the different individual outcomes, while a histogram would plot the frequency of outcomes that fit in a specified range. For more in-depth information about this, see our dictionary article on the histogram.

Basically, if a team lead needs to see the probability distribution of product variations, they could wait until all the product is produced and then log the differences in output afterwards… OR they could use this type of check sheet to monitor probability distribution as the process is underway.

Before filling out this check sheet, the supervisor should decide which “bins” should be designated for different thresholds of variability. These bins represent the columns of the check sheet. Then, as output is produced, the supervisor will sort each group of output into the proper bin on the check sheet.

Final analysis includes looking for bell curves or specification limits within the check sheet data.

Quantify defects by location

This type of check sheet is a map, diagram, or drawing of the final manufactured object viewed from every angle. The quality control worker then looks at the finished product on the assembly line and compares it to the picture, making marks on the picture where defects occur on the actual product.

This evaluation allows manufacturers to pinpoint the spatial frequencies of types of defects like bubbles or material faults.

Quantify defects by cause

This check sheet works hand-in-hand with the Ishikawa (Fishbone) Diagram, because both are used to identify the cause of defects once they have been noticed by workers. This check sheet includes several columns with suspected causes of defects. The 5M framework is oftentimes used to fill out these columns.

Instead of ticks or checks, the supervisor will use different symbols to represent different types of defects. Then, they will observe the production process and write down a symbol in the columns that represents different combinations of potential defects.

This data collection is very qualitative, especially from the instinct of the supervisor attributing symbols to what they think may be the problem, but it nonetheless is a valuable way of uncovering the root causes of production issues.

Keep track of multi-step processes

Last but not least, this is the simplest type of check sheet – you probably encounter this type frequently. It consists of a list of steps that must be followed (oftentimes in the exact order shown) to complete a task. These steps can be “checked” off once done to help the user navigate a longer or more involved process.