22: Design Output Issue
Definition/Typical Issues
Was the design output, such as drawings and specifications, incomplete? Was there a failure to consider all operating conditions (normal, startup, shutdown, emergency) in the design? Were the design documents difficult to read or interpret? Did the final design output fail to include all changes? Were there differences among different output documents? Did the design output fail to address all requirements specified in the design input?
Examples
Example 1
- A valve failed because the design output specifications were incorrect. The detailed design output did not agree with the design input. The design input stated that the valve must operate in a corrosive environment, but the design output specifications did not indicate this condition. Therefore, the valve was constructed of improper materials.
Example 2
- A line ruptured because a gasket failed. The gasket was constructed of the wrong material because the gasket was not compatible with all the chemicals that would be in the line during different operating conditions. Although all the chemicals were listed in the design specification, the gasket specified by the designers was incompatible with some of the chemicals in the system.
Example 3
- A pump did not provide the necessary cooling water during an emergency. The pump was sized incorrectly because the final design specification did not include changes identified in the hazard analysis.
Typical Recommendations
- Include experienced operations and maintenance personnel in design reviews to help ensure that all possible operating conditions are considered in the design.
- Include designers in construction and pre-startup reviews to help ensure that design information is properly interpreted.
- Conduct an independent technical review of the final design to help ensure consistency among various design documents.
- Include satisfaction of design input criteria as a specific review team item during design reviews.
Cross-References
| Version 10 Element(s) | |
|---|---|
| Node ID | Node Name |
| 17 | Design Output LTA |
| RBPS Element(s) |
|---|
| Compliance with Standards |
| Maritime Element(s) | |
|---|---|
| Node ID | Node Name |
| 26 | Design Output Issue |