Warranty Analysis

[HFolsent]

I have a weibull distribution for my units and I have a general idea as to how many units are in the field, how do I predict my risk?

[RS Support]

If by risk you mean the expected number of failures see the discussion at http://www.weibull.com/LifeDataWeb/warranty_analysis.htm . This method can also be utilized to determine risk, as probability of failure for any population of a given age.

Weibull++ 6 has a utility that can perform this analysis automatically. Alternatively one can set up a spreadsheet, using the same formulations to arrive at that answer.

[R.A.Madgulkar]

If I have a data of field failures as follows

Repairs per hundred units in last eight quarters for a perticular component as 23,54,17,21,27,15,17,0,0 and number of engines built in these resepective quarters as 576, 589,612,743,589,755,733,800 how can I predict the RPH(repairs per hundred) for next four quarters assuming I am not using any readymade software for this?

[RS Support]

Along with software use -- the document mentioned in the prior email (as well as other pages in the on-line textbook) show the equations (methodology used).

In your case some more information will be required (i.e. what population the failures came from) to use this methodology.

[Shaique Ali]

I have some warranty data for the last 1, 2, 3, 4 years for a automotive component. I have access to all of my failures points distibution from the warranty data in terms of MIS and Mileage. Unfortunately I have no access to track the non-failure points. Or in other words that I dont have access to track my suspendid distribution in terms of MIS and Mileage. I know the volumes that I produced over the above defined period of time. Please advise I could come up a very good estimate of Reliability

[Christian L]

I have to build a stress test to get confidence on my product warranty. I am looking for info, what types of tests (T&H, T/C, HTB,....) I have to run, how to calculate Ea for my system, how many systems I have to put on stress to have 50%CL, 90%CL of my warranty objective.
Thanks,
Christian

[Pantelis]

Christian:

I would recomend going through http://www.weibull.com/acceltestwebcontents.htm

[Pantelis]

Shaique... I know this is late... I just noticed your posting... but here it goes for the benefit of others that mey be looking at this:

You will have to make some assumptions. I simple assumption is to look at the average mileage per year and use that in combination with the shipped volumes to come up with a suspension population in mileage terms.