Design Review Based on Failure Mode
History: DRBFM
Tatsuhiko Yoshimura developed the following method in 1997
The purpose is to find our errors, which occur as a result of intentional changes and the resulting unintentional changes in the product and process.
Features
- Less formalism, hence concentration on finding the problem
- The working means and the procedure should stimulate the creativity of the engineers
- DRBFM was integrated in the GD³ philosophy
What does GD³ stand for?
DRBFM Process
Procedural course of DRBFM
Analysis of the change (1-4)
- Observation of the desired changes and identification of undesired effects
Analysis of the risks (5-6)
- Discussion about the effects on internal and/or external customers
Developing and evaluating solutions (6/7)
- The objective is to achieve successfully the desired change and at the same time effectively minimizing the risks.
Defining measures (7)
- Based on verfications and validations
- Developing and tracking the measures
Success monitoring (8)
DRBFM working means
DRBFM-form sheet
- Includes all changes, the risks emerging from them and all measures
Checklist of changes (Awareness-Sheet)
- AInstructions to identify desired and resulting undesired changes
Table of changes (Change Comparison Table)
- Comparison of the design until now and the modified design, makes the actual change clearh
Table of functions (Function Focal Point Table)
- Describes the effect of the changes on the product systematically
Matrix of changes/functions (Change and Functions Concern Points Table)
- Comparison of the functions relevant for the customer and the desired and resulting changes, thus shows the risks
The DRBFM-form sheet
Analysis of the Cause - Failure – Effect relations.
- Presentation: Desired changes and the resulting undesired effects
- Presentation: Effects on the function and risks
- Determining measures for reducing the identified risks
Design Review
- Presentation: Specification of the required measures and determining the responsibility
- Presentation: Evaluation of the effectiveness of the determined measures
The DRBFM-form sheet – Analysis of the Failure chain
1 Description of the desired and undesired changes
- Part / Component name
- desired changes and reason for changes
- Undesired changes, which arise from the desired changes, with justification
Describe all specifications in detail
2 Description of the function
- Describe the function of the part as much precisely as possible
- Under which working conditions does the function occur?
- Describe all functions precisely
3 Description of the Possible Failure mode due to the change
- Describe the risks precisely
- Collect other fears in team work
4 Description of the Occurance and the Failure causes
- W-questions: When? / How often? / Where? / …
- Negating functions
- 5 x Why questions (W-method), in order to find out the true cause (measures are effective only if they are directed against the causes)
5 Consequences
- Which consequences arise for the defined customers?
6 Current measures to Prevent Failures
- Define measures
- Follow thereby the operating conditions and requirements
- When required, defined other measures (=>7)
7 Determined measures (Results of DRBFM)
- If Point 6: „Present measures“ are not sufficient, additional measures are developed
- Naming responsible persons and deadlines
8 Determining effectiveness of the measures
- For every measure from the DRBFM, the following is determined
- what was done
- when and how
- results
