Recent Question/Assignment

KNE240 Assignment
In order to estimate warrantee costs, 70 prototypes of a new product design are tested with the test terminated after 55 failures. The failure times were recorded in 100s of operating hours. Failure mode B is failures due to manufacturing defects. Failure mode C is failures due to premature wearout of parts. All other failures are recorded as mode A. The following results were obtained:
Failure time Failure
mode Repair/ Replace cost Failure time Failure
mode Repair/ Replace cost Failure time Failure
mode Repair/ Replace cost Failure time Failure
mode Repair/ Replace cost
1 A 11% 173 A 12% 273 B 17.2% 532 C 14.5%
3 A 10% 174 A 18% 283 C 13% 547 A 17%
9 A 9.5% 185 B 16% 301 B 16% 580 A 38%
30 A 12.3% 190 B 19% 319 C 14% 667 C 14.2%
60 C 17% 199 A 7% 333 B 17% 828 C 13.6%
99 B 21% 202 A 5% 335 B 16.8% 840 A 18%
101 C 18.5% 205 B 13% 344 B 17.3% 859 A 3%
130 C 14% 210 B 15% 349 B 15.9% 920 C 14.1%
136 A 20% 214 C 16.3% 380 B 16.4% 1182 A 21%
137 A 25% 222 B 17% 391 B 16.5^ 1195 C 15%
146 A 27% 260 B 15.6% 457 C 12% 1391 A 17%
155 A 51% 262 C 14.5% 478 C 13% 1443 C 13.5%
169 A 47% 267 B 15.9% 491 A 22% 1466 C 14.1%
171 A 34% 269 B 16.2% 512 B 17.7%
The repair or replacement costs are measured as a percentage of the manufacturing cost of the product.
You are the reliability engineer responsible to provide analysis and report to the design manager. You need to model the product failure and repair/replacement costs and based on that to give professional advices on sale price, warrantee terms, and structure to ensure a 10% profit margin with maximum reliability for 50000 operating hours.
You can consider selecting some from, but not being limited to, the following techniques to include in your report: Histogram modelling, reliability data analysis and empirical data modelling, parameterised reliability modelling, Weibull analysis, FTA, reliability modelling of systems including multiple components, design life, warrantee of system, warrantee scheme for individual mode, conditional reliability, etc.
The report should be informative, logical, and concise. The total page number should not exceed 10 pages excluding the title page and the references page.
Assessment criteria:
Items and weights HD
=8/10, 13/15, 16/20, 24/30 DN
7/10, 11~12/15, 14~15/20, 21~23/30 CR
18~20/30 PP
5/10, 8/15, 10~11/20,
15~17/30 NN
=4/10, 7/15, 9/20, or
14/30 Your Marks
Introduction (10%) Background, aim and method are logically and clearly organised to promote the value of the report and point out the expected outcome of the report. Introduces the background, aim and method are clearly organised to motivate the report and the expected predict outcome. Introduces the background, aim and method are included with logical connection among them Introduces the background, aim and method are included. No significant error. Either background, aim, nor method are not touched, or included significant error
Use of technology (30%) -Appropriately and correctly implemented all relevant methods discussed in KNE240 -Analysis and discussion are appropriately included
-all components are discussed with major ones appropriately identified and analysed -Point out at least one possible method not learnt in KNE240 -Appropriately and correctly implemented at least three reliability methods. Those methods reflect empirical method, parametric method and system method
-At least four major components are appropriately identified and analysed -Appropriately and correctly implemented at least three
reliability methods -At least four major components are correctly identified and analysed. -Correctly implemented
at least two reliability methods
-At least two major components are identified and analysed. The report either does not include two reliability methods learnt in KNE240 or contains significant error
Organisation of analysis (20%) Analysis, explanation, and discussion are organised nicely and concisely to provide a smooth reading flow. Analysis are well organised with appropriate level of discussion and explanation Analysis are well organised logically without any logical error Analysis are organised logically without significant logical error Analysis are not included nor organised logically
(15%) Data are presented clearly and intuitively, which make the report informative and convincing Tables and plots are included and nicely integrated with the context. Important tables and plots are
included with appropriate field title Include table and graph Data is not presented in any form other than text.
Conclusion (15%) -A complete summary
-Provide guidance of use
-identify potential impact of the report and possible future improvement of analysis -a complete summary of report -provide guidance of the use of report outcome -summarises the major aspects of report
-Identify the possible value of the report -Includes relevant conclusion One of the following
-No conclusion -Conclusion contains
-Conclusion not relevant to context
General writing (10%) -Proper use of language and vocabulary. -ideas are appropriately and effectively explained and discussed.
-No noticeable issues can be identified in all aspects of writing. -ideas are appropriately explained -no noticeable grammar and usage issue can be identified -Ideas are effectively conveyed -No significant grammar nor usage issues, Explains the basic aspects of the report Include significant issues that impact the understanding of the report