1 ME Spring 2015 Systems Engineering, Part II Session 8 5 February 2015 Mr. Larry Hopp, CPL © Copyright 2013

2 Agenda Discuss Maintainability Ch. 13

3 Maintainability Analysis Methods R&M Trade-0ff Maintainability Predictions Reliability-Centered Maintenance (RCM) Level-of–Repair Analysis (LORA) Maintenance Task Analysis (MTA) Total Productive Maintenance (TPM)

4 Reliability and Maintainability Trade-Off Evaluation Trade-offs can look at many different things Alternative designs to meet different spec requirements Lowest cost that meets the requirements.

5 Maintainability Prediction MIL-HDBK 472 Maintainability Predictions Dated 12 Jan 1984 –Done at various times during the design process –Gives various maintenance time parameters MTTR, Corrective, Preventive, Active –Requires a variety of information Resources –Personnel, training, test and support equipment, supply support, transportation, facilities etc

6 Reliability-Centered Maintenance MIL-STD 3034 Reliability-Centered Maintenance (RCM) Process Dated 21 Jan 2011 –A method for determining maintenance requirements based on the analysis of the likely functional failures of systems/equipment having a significant impact on safety, operations, and life- cycle cost. RCM supports the failure management strategy based on its reliability and operating context.

Copyright ©2011, ©2006, ©1998 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Systems Engineering and Analysis, Fifth Edition Benjamin S. Blanchard Wolter J. Fabrycky Figure Simplified RCM decision logic.

Copyright ©2011, ©2006, ©1998 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Systems Engineering and Analysis, Fifth Edition Benjamin S. Blanchard Wolter J. Fabrycky Figure The RCM analysis model and its interfaces.

9 Level of Repair Analysis (LORA) MIL-STD 1390D Level of Repair Analysis (LORA) Dated 19 Jan 1993 Helps determine if an item is repairable and at what maintenance level. Free computer models are available –JAM for LORA – Navy –COMPASS – Army Many Commercial versions

10 Level of Repair Analysis (LORA) Most effective maintenance and support structure for a system through iterative evaluations of both economic and noneconomic considerations. Determine the least cost feasible repair level or discard alternative and to influence the equipment design in that direction. Start early in the design effort and can be iteratively accomplished as the equipment design becomes more refined.

Copyright ©2011, ©2006, ©1998 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Systems Engineering and Analysis, Fifth Edition Benjamin S. Blanchard Wolter J. Fabrycky Figure Basic system concepts.

Copyright ©2011, ©2006, ©1998 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Systems Engineering and Analysis, Fifth Edition Benjamin S. Blanchard Wolter J. Fabrycky Figure Repair versus discard evaluation (Assembly A-1).

Copyright ©2011, ©2006, ©1998 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Systems Engineering and Analysis, Fifth Edition Benjamin S. Blanchard Wolter J. Fabrycky Figure Economic screening criteria.

Copyright ©2011, ©2006, ©1998 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Systems Engineering and Analysis, Fifth Edition Benjamin S. Blanchard Wolter J. Fabrycky

Copyright ©2011, ©2006, ©1998 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Systems Engineering and Analysis, Fifth Edition Benjamin S. Blanchard Wolter J. Fabrycky Figure Level-of-repair analysis procedure.

16 Maintenance Task Analysis Evaluate a system –Identify steps and resources –Assess the configuration –Corrective and Preventive Maintenance –Analyze results –High level during conceptual design –More detail as the design progresses

17 Maintenance Task Analysis Existing System –Evaluate the current configuration –Identify the high cost contributors –Look at cause and effect relationships –Identify possible cost effective improvements –Make recommendations

18 Total Productive Maintenance Manufacturing based factory maintenance Life-cycle approach Maximize your equipment –Preventive versus corrective maintenance –Predictive maintenance Get everyone involved –Get a commitment

19 Maintainability Demonstration MIL-STD 471A Maintainability/Demonstration/Verification Dated 27 March 1973 Part of System Test and Evaluation –Part of Type 2 testing –Assesses logistics support

20 Demonstration Method 1 Process –Induce a failure without knowledge of test team –Tech check out equipment –Corrective maintenance –Collect data Maintenance procedures Logistics Support M ct and M max

21 Demonstration Method 2 50 Corrective, 50 Preventive actions Mean Active Maintenance Fixed Sample size Calculate Mean Active Maintenance Tasks

22 Maintainability Assessment Type 3 & 4 testing Validation of requirements Note deficiency –Corrective action –Design Modification

23 Chapter 13 Thursday 12 February –Homework Chapter 13 Problems 2, 5a – e, 12, 14, 23 Tuesday17 February –Quiz #2 Chapter 13 Thursday 19 February –CP2 Maintainability CDR

24 Trade Off Techniques –List all candidate approaches Many are clearly not feasible Analyze those that are feasible –Define the problem –Identify the ground rules and constraints –Describe the feasible alternatives –Define an approach for problem resolution –Select the appropriate evaluation criteria –Identify the potential areas of risk and uncertainty –Select the appropriate methods or techniques

25 Trade Off Techniques –Collect Data Allocation results Predictions Forecasts Historical data –Conduct Sensitivity analysis –Define areas of risk –Propose a recommended approach

26 Maintenance Task Analysis Identify resources –Personnel and training –Test and Support equipment –Spares/repair parts and inventories –Transportation and handling requirements –Facilities –Technical data –Computer resources

27 Maintenance Task Analysis Detail Design –Design Data –Drawings –Component part and material lists –Reports –Define Maintenance Tasks

Copyright ©2011, ©2006, ©1998 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Systems Engineering and Analysis, Fifth Edition Benjamin S. Blanchard Wolter J. Fabrycky Figure The MTA and supporting tools/models.

29 Maintainability Demonstration Joint between the contractor and the buyer Accomplished during the latter part of detail design See if specific maintainability contractual requirements have been met Check for design deficiencies Have a formal test plan or procedure

30 Maintainability Demonstration Have a formal test plan or procedure –List of tasks –Composition of test team and each members responsibilities –List of support material, facilities, and documentation –Demonstration procedures and statistical test methods –Ground rules for fault insertion, rules regarding retest if a failure, funding any design changes, exclusion from the demo

31 Maintainability Demonstration Have a formal test plan or procedure –Qualitative and quantitative parameters to be demonstrated –Timing of the demo –Describe the location Use an environment as similar as possible to the actual operational and maintenance environment –Define the levels of maintenance –Establish what criteria will be tested –Verify maintenance tasks

32 Maintainability Demonstration Have a formal test plan or procedure –Verify all of the necessary logistics resources are available Technical documentation Test Equipment Tools Support equipment Skilled personnel –Equipment should be similar to production equipment –Look at the adequacies or inadequacies of log spt