Reliability Target Setting By André Vondran

Reliability Target Setting is accomplished during the MSRP Planning Stage. 

It often utilizes information gathered during the Concept Approval Stage by the Market Studies / Research task. 

It involves identifying the appropriate reliability goals for the product development that is about to be undertaken. Reliability Targets are set based upon customer requirements, competitor information and cost/technology tradeoffs.

Purpose: Reliability Target Setting is the starting point for the entire Reliability project. It establishes the reliability goals that will be used to define the Reliability Growth Plan and to set the basis for Reliability Testing.

Requirements: This task needs to be applied in all cases of new hardware development where the customer requirements and application environments need to be well understood to provide a confidence in the success of the product in the marketplace.

Prerequisites: The key inputs for this task are historical information for products that are comparable to this new product, both in terms of DDC hardware and competitor's hardware. These data are used together with a good understanding of the customer requirements and application environments gathered during the Market Studies / Research task to determine necessary, but realistic reliability goals for this hardware development.

Organization

Responsibility: The Owner of this task is the Reliability Engineer. Participation is required from the Product Line General Manager as well as representatives from Sales, Product Engineering, Application Engineering and Customer Assurance. This task will be integrated into the overall Goal Setting being carried out by other elements of the Organization.

Timing: This task must be completed during the Planning Stage as defined in MSRP 2.0. Its outputs serve as the foundation for the Reliability Allocation, the Reliability Growth Plan and the Reliability Testing planning tasks to be performed in the Planning Stage and as an input to the Verification and Validation Planning.

Procedure

Steps: The Reliability Target Setting is directed toward establishing specific goals for the hardware to be developed. These goals will consist of some or all of the following (using an engine development as an example ):

· A mission time, expressed as the number of hours or miles over which the desired reliability is to be achieved [e.g. 100,000 miles ]

· A Reliability Goal, expressed as a probability of success over the specified mission time [ e.g. R ( 100,000 ) = .65 ]

· An All Repair Rate Goal, expressed as the total number of repairs per unit [ e.g. Repairs / Engine @ 100,000 miles = .50]

· A Durability Goal, expressed in terms of a required B - life level [e.g. A B10 life greater than 250,000 miles.]

In these examples, a mission time of 100,000 miles can be the warranty period to be defined for this engine. The R( 100,000 ) = .65 means a customer with 100 engines will have 40 that require at least one repair by the end of the 100,000 miles. The Repairs/Engine @ 100,000 miles = .50 means that these 40 engines that require one or more repairs each, will require a total of 50 repairs. The B10 life > 250,000 miles means that 90% of the engines will run beyond 250,000 miles before rebuild.

Depending on the nature of the project, the Target Setting Task may be further developed to provide separate goals dealing with "major" and "minor" repairs or some other measure that deals with the severity of the failure. Likewise, goals dealing with repair cost can also be identified at this time as part of this process, e.g. warranty accrual levels.

The first step in this process is to identify specific production hardware that is currently in customer's hands that is similar to the nature and application of the hardware to be be developed. 

This can consist of DDC as well as competitor's products. 

The next step involves analyzing the reliability performance of this current hardware through reviews of warranty experience, historical data, specialized product testing and the word from the marketplace. 

At the same time, directed inputs from the Market Studies / Research task reflecting the perceived needs of the customer, are also incorporated. All of this information is brought to a thorough review of the Cross-Functional Team, where the aspects of cost / technology tradeoffs can also be incorporated into a CFT determination of the specific, quantified reliability goals.

Final Output: The output of this task is a report that identifies the specific, quantified reliability goals to be used for this new hardware development, together with any associated conditions for their application.

Conclusion

The outputs of this task provide the foundation for the other Reliability Engineering tasks in the Planning Stage for this project:

· Reliability Allocation

· Reliability Growth Plan initial development

· Reliability Testing plan

· Initial work on the system Failure Mode and Effects Analysis

Best Regards · Mit freundlichem Gruß · Cordialmente ·