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1、Certified Reliability Engineer. Ch 8. Data Collection & Analysis. Industrial Engineering & Management Systems Research Center. - 1 - Types of Data. CRE Primer p2-3 Variable Data. Variable data is continuous. This means that the data values can be any real number, for example, 1.037, -4.69, 84.35. Me
2、asured data (variable data) are answers to questions like “how long,“ “what volume,“ “how much time“ and “how far“. Attribute Data. Attribute data is discrete. This means that the data values can only be integers, for example, 3, 48, 1029. Counted data or attribute data are answers to question like
3、“how many“ or “what kind.“ Locational Data. Locational data simply answers the question “where.“ Chart that utilize locational data are often called “measles charts“ or concentration charts. - 2 - Censored and Incomplete Data Sets. CRE Primer p4-5 Right Censored. The value of the censored items in t
4、he data set are known to be greater than the censored value. Left Censored. The value of the censored items in the data set are known to be less than the censored value. Single Censored. There is only one point at which censoring occurs. - 3 - Censored and Incomplete Data Sets. CRE Primer p4-5 Multi
5、ple Censored. There is more than one point at which censoring occurs. Time Censored (Type ) Testing is ended after a predetermined amount of time. Failure Censored (Type ) Testing is ended after a predetermined number of failures. - 4 - Reliability Data Sources. CRE Primer p6 Reliability Data Source
6、s. Failure analysis records. Failure reports. Reliability group test records. Other test records. Manufacturing results. Manufacturing failure and yields. Installation reports. Corrective maintenance requests. Preventive maintenance logs. Repair or warranty actions. Complaint centers. Unit repair lo
7、gs. Part depot usages. Request for support. Request for upgrades. Customer feedback forms. Customer surveys. - 5 - Data Collection Methods. CRE Primer p7-10 Objectives of Data Collections. Demonstrate reliability to customers. Demonstrate reliability internally. Validate vendor supplied items. Valid
8、ate internal process. Enhance product safety. Compare designs. Compare components. Determine competitive performance. - 6 - Data Collection Methods. CRE Primer p7-10 Some Guidelines for Data Collection. Define precisely what is to be measured. List all the important characteristics to be measured. C
9、arefully select the right measurement technique. Construct an uncomplicated data form. Decide who will collect the data. Arrange for an appropriate sampling method. Decide who will analyze and interpret the results. Decide who will report the results. - 7 - Data Collection Methods. CRE Primer p7-10
10、Data Collection about Failures or Preventive Actions. Identify of personnel performing the service. Type of service call (corrective or preventive). Initial equipment (inoperative) state. Misused, stressed, or damaged state. User injury (requires user name and contract information) Amount of equipme
11、nt usage. Environmental conditions, especially if they are abnormal. Actions taken to restore the product. Parts used to restore the product. Test and calibration results. Relevant time factors. - 8 - Data Collection Methods. Other Resources Failure Data Collection Requirements. 1. Date and time of
12、failure. 2. Operation conditions at the time of failure, environmental conditions as well as required fluid levels and condition of typical preventative maintenance items. 3. Description of the failure mode. How did the failure manifest itself ? What was the status of the product when the failure oc
13、cured ? What was the effect of the failure on the rest of the system, and did the failure affect safety ? - 9 - Data Collection Methods. Other Resources Failure Data Collection Requirements. 4. What were the necessary actions to repair the failure ? What equipment was necessary for repair, how long
14、did the repair take, were there any unusual occurrence, can the effect of the failure on the rest of the system be logically explained by the failure or was there an unanticipated secondary failure ? 5. What was the active operating time of the equipment ? Did the equipment spend any significant amo
15、unt of time on standby or in storage ? 6. Equipment operator along with classification and skill level. 7. Initial failure cause determination. Was the failure the result of a design fault, an improperly performed maintenance action, poor quality assembly, or part ? - 10 - Data Collection Methods. Other Resources Failure Data Collection Requirements. 8. Following the initial investigation there should be a formal failure analysis where appropriate to verify the initial failure classification or reclassify the root failure cause. 9. Following the root failure cause determinati
