Many times during execution of project work, we carry out defect rectification for the problems highlighted by Control Quality / Validate Scope process. After the corrective action, the defect is repaired and it pases the internal/customer inspection. Will the reliability of this repaired product be same over its operating life as that of a product that is First Time Passed in all inspection stages? It certainly won't be same. But is there any way to quantify the reduction in reliability due to defect repair? Saving Changes...
It really depends on the nature of the defect and resulting repair. If a defective component is replaced by a functional one (e.g. swapping a blown fuse for a good one), there should be no reduction in reliability. If the fix is more of a workaround or involves reusing the same component, then there might be some reduction in lifetime or performance which results.
Quantifying it will be a function of:
1. Figuring out what you want to measure - is it the effective working life of the product, mean time between failures or some other metric?
2. Gathering a baseline of data from a statistically representative sample of widgets which have had no defects
3. Gathering data from a statistically representative sample of widgets which were repaired
4. Comparing the two using a test such as a two sample t-test (assuming the populations follow a normal distribution)
First, you have to define what quality means to your organization. Second, somebody have to define the quality attributes for the product. As project manager, you are not accountable for that. You are only accountable for managing all related activities to assure that product quality attributes have been achieved. That´s all that you can do as project manager. All related to product (except the activities to create it) are responsability of the business analyst Saving Changes...