Sometimes I visit a Japanese website called “monodukuri.com” and answer to a question which a questioner asks on the website. I recently answered to a question regarding the QFD file management. So I summarized my answer here before I forget about it.
The questioner has the following problems:
- Each QFD is created by individual in the organization
- Because of that, the quality of QFDs vary, and there are missing items
- Because of that, a rework in the development process happens
- The QFDs created in the historical projects never be re-used
Then, the questioner asked if a database system which can effectively use the historical QFDs is available in the market or not.
If the questioner wanted to manage only the items in the QFDs, he can use a standard relational database system in the market, and achieve his goal with carefully designed data structure.
But the questioner needed a database system for QFD. I didn’t know any relational database system for QFD, so I tried to explain my example instead.
1. A problem with scattered QFD files and FMEA files
I had a similar problem in past, but it was not only with the scattered QFD files but the scattered FMEA files. My problem was:
- A new QFD file and FMEA file were created from scratch for every new product development projects
- The person in charge saved those files in his/her PC storage or on the network storage
- The number of scattered files was increased
- Reusing of the scattered files was very difficult
Then, these problems appeared in the forms like below:
- Decrease productivity (i.e., the lead-time of QFD/FMEA creation is long, and a rework in development process occurs)
- Degrade quality of QFD/FMEA with missing items
2. File Management using Master files and Differential files
In many cases – fortunately or unfortunately – 80% or more of requirements for a new product development could come from the existing technology or products, and around only 20% of requirements could be really new. In other words, around 80% of items in the historical QFD and FMEA can be reused by the new product development project.
Based on the historical QFD files and FMEA files, I created the master QFD files and the master FMEA files for typical product types. These master files looked like the templates with populated data (i.e., QFD items and FMEA itesm).
A new product development project can use these master files which could cover 80% of the requirements and the risks in the new development.
The rest 20% of requirements is called NUD requirements because they are New, Unique or Difficult. A new QFD and a new FMEA are created only for these NUD requirements, and such QFD and FMEA are called the differential QFD and the differential FMEA.
Therefore in the new product development, A master QFD (or FMEA) is selected and modified if necessary, then a differential QFD (or FMEA) is created to cover all requirements (or risks). This approach prevent a missing item and a rework in the development process, and shorten the lead-time to create the file (Increase both productivity and quality).
3. Update Master files
Once the master files were created, these master files are continuously updated at every new product development project so that the quality of the master files increase. The master files are placed in SharePoint site so that a motivated person who wants to create a QFD and a FMEA better and faster can use them.
This approach with the master files and the differential files is very simple and balanced in terms of cost, efforts, and results.