A data collection plan is a detailed document. It describes the exact steps as well as the sequence that needs to be followed in gathering the data for the given Six Sigma project. This document is important because the people that design the data gathering plan are not the same people that will actually be collecting the data. Firstly the document ensures that every one on the six sigma project team is on the same page with regards to the data plan. Secondly it ensures that this information is correctly transmitted to the people in the organization that will actually provide for the data needs. Here are the typical components of a data collection plan:
Purpose: The first thing that needs to be clarified before any effort is done is the purpose. The most common purposes include finding whether a process is stable? Whether a process is capable? Or whether a particular input will work better for a process than a previously used input? In every case the purpose needs to be defined crystal clear.
What?: What signifies the metrics, the measurements for which need to be recorded. As we already know that while metrics are being specified, we should provide the exact operational definition and define the way calculations are going to be made to avoid confusion. Failing to do so can make the numbers incomparable.
Type of Data: Whether the data is continuous or discrete needs to be mentioned. The people executing the data plan will need this information. Also the sub-type of data like binary, ordered pairs etc need to be mentioned and explained to the people collecting the data.
Who: In most modern day six sigma projects, the data to be collected is done by a machine. This is either done by a shop floor machine or a workflow software which is precisely recording the data for each step. However there are people who are responsible to program the machine to collect the data and display it in a format which is acceptable to the Six Sigma Team. The who therefore refers to liaising with the person in charge of the software to ensure the data is available and in the correct format.
Where: Where may not refer to the physical location as much as it refers to the location within the process. The data collection plan must explicitly specify where in the process must data be collected from.
Frequency: Data for process improvement endeavours need to be collected over a period of time. The data collection plan tells exactly at what frequency the data needs to be collected. This is a part of experiment design and must be adhered to by the data collection team without the slightest of changes.
How to Display: The data collection plan also explains the format in which the collected data needs to be displayed to the Six Sigma team. Most probably a graphical method is used because it is intuitively easier to use.
There may be only statistical expert in the Six Sigma Team who actually prepares the Six Sigma Plan. However this document ensures that the expertise is used throughout the process.