No Reliability Department present
Statement 10:
We do not have a Reliability Department
41% of the participants indicated they did not have a reliability department.
Is that bad? It depends. If you develop products a reliability department is more or less mandatory. Most participants worked for a company developing their own products, so it i sad to notice that 41% did not that reliability department. There should always be a reliability department present somewhere in that company. Remember that in this context a company has a wider meaning than your own company. See the article Reliability versus unreliability.
A reliability department does not have to physically present in house but at least it should be available eg. as consultancies even with the suppliers or customers. Someone should take care of reliability. Having a reliability department is usually expensive, but expensive is a relative issue. A few million dollar disaster caused by a failure which could have been avoided is often more expensive than the investment in reliability engineering and equipment. The problem is that a reliability department is not about making money but about saving money! That is difficult to forecast but not impossible.
A Reliability department consists of various specialist like mechanical, electronic, chemical etc. depending on the kind of products one develops. These specialists have a few subjects to take care of:
- The concept of the design
- Expected life expectance
- Reliability during life
The reliability department also acts as a knowledge center. Especially with large companies reliability problems show some synergy.
The concept of the design
The design needs to be judged on (un)expected reliability parameters. This means an analysis must be done to find the weakest elements within a design. Are the right components used in the right places? Are there components with unknown reliability parameters? Also checks if the expected reliability (failure rates) are conform the reliability budget.
The expected life expectance
All products will eventually die. Therefore it is important to know what stress parameters can be expected during its entire life. That knowledge in relation to the strength of the product gives clues for the expected life. If this expectance is too low one can consider:
- redesign the product
- add redundancy techniques
- create opportunities for a timely replacement via preventive maintenance.
Reliability during life
This is most challenging part and requires a lot of knowledge and experiences in the common failure modes as well as to think about test methods to find possible failure mechanisms as early as possible.
The quality department
Most companies do have a quality department. Usually they do only the standard test as required like humidity tests, temperature cycling, etc. If the products withstand these test they are released for delivery.
However it is an illusion to assume that this type of release also means that the products are reliable. These standard test only tells you if the product is unreliable, not if it is reliable enough. With no failures found during the tests there is no information on failure modes. It indicates it is possible to create it. That is quality, not reliability.
Quality department usually has test equipment for the standard tests or use outside services. If they are in house also the reliability department can use them but in a lot of occasions the priorities for reliability engineering collides with the priorities of the owner of the test equipment, so it can be conflicting. It also depends on the way the company is organized
Quality department also has to play an important role in cases like safety requirements. There are too many of these to be present in the brains of all developers. In stead quality department must play an important role, not testing on the final product only but be present from the conceptphase onwards.
It happened that a product could not be released because a safety requirement of a transformer was not met. That same transformer was already present from the beginning of the development more than one year ago and never changed. Quality department refused to do any test unless it is a final product. That was the official procedure. This caused a mandatory delay in Time to Market. The development department got the blame and the quality department were praised to have it found in time! In time? Go figure...