Matakuliah
Tahun
Versi
: H0204/ Rekayasa Sistem Komputer
: 2005
: v0 / Revisi 1
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Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa akan mampu :
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Outline Materi
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Studi Kasus 2 : Repair versus Discard Evaluation
Bacalah studi kasus berikut ini
• In expanding the maintenance concept to establish criteria for equipment design, it is necessary to determine whether it is economically feasible to repair certain assemblies or to discard them when failures occur. If the decision is to accomplish repair, it is appropriate to determine the maintenance level at which the repair should be accomplished (i.e. intermediate maintenance or supplier/ depot maintenance).
• Suppose that a computer system will be distributed in quantities of 65 throughout three major geographical areas. The system will be utilized to support both scientific and management functions within various industrial firms and government agencies. Although the actual system utilization will vary from one consumer organization to the next, an average utilization of 4 hours per day (for a 360-day year) is assumed.
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Studi Kasus 2 :
Repair versus Discard Evaluation
• The computer system is currently in the early development stage, should be in production in 18 months, and will be operational in 2 years. The full complement of 65 computer systems is expected to be in use in 4 years and will be available through the eight year of the program before system phase out commences. The system life cycle, for the purposes of the analysis, is 10 years.
• Based on early design data, the computer system will be packaged in major units with a built-in test capability that will isolate faults to the unit level. Faulty unit will be removed and replaced at the organizational level (i.e comsumer’s facility), and sent to the intermediate maintenance shop for repair. Unit repair will be accomplished through assembly replacement, and assemblies will be either repaired or discarded. There is a total of 15 assemblies being considered, and the requirement is to justify the assembly repair or discard decision on the basis of life-cycle-cost criteria.
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Studi Kasus 2 :
Repair versus Discard Evaluation
• The stated problem primarily pertains to the analysis of
15 major assemblies of the given computer system configuration to determine whether the assemblies should be repaired or discarded when failures occur. In other words, the various assemblies will be individually evaluated in terms of (1) assembly repair at the intermediate level of maintenance, (2) assembly repair at the supplier or depot level of maintenance, and (3) disposing of the assembly. Life-cycle costs, as applicable to the assembly level, will be developed and employed in the alternative selection process. Total overall computer system costs have been determined at a higher level, and are not included in this example.
• The objective is to be consistent in analysis approach and in the use of input cost factors to the maximum extent possible and where appropriate.
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Studi Kasus 2 :
Repair versus Discard Evaluation
• The summary results for all 15 assemblies are presented in table 22.1
Assembly
Number
A - 9
A - 10
A - 11
A - 12
A - 13
A - 14
A - 15
A - 1
A - 2
A - 3
A - 4
A - 5
A - 6
A - 7
A - 8
Policy Cost
Repair at
Intermediate
Cost ($)
Maintenance Status
Repair at
Supplier
Cost ($)
61,665
58,149
85,115
85,778
66,679
65,101
72,223
89,348
78,762
63,915
67,001
69,212
77,101
59,299
71,919
1,071,267
64,952
51,341
81,544
78,972
61,724
72,988
75,591
78,204
71,444
67,805
66,158
71,575
65,555
62,515
65,244
1,035,612
Decision
Discard at failure Cost
($)
187,475
122,611
73,932
65,071
95,108
89,216
92,114
76,222
89,875
97,212
64,229
82,109
83,219
62,005
63,050
1,343,449
Repair
– intermediate
Repair
– Supplier
Discard
Discard
Repair – Supplier
Repair – intermediate
Repair – intermediate
Discard
Repair
– Supplier
Repair – intermediate
Discard
Repair – intermediate
Repair – Supplier
Repair – intermediate
Discard
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TUGAS / Diskusi
Dari data yang diberikan,
• Buatlah model operational requirement, maintenance concept, and program plan
• Berikan rekomendasi untuk setiap item (dari A-1 sampai A-15) dalam mempertimbangkan maintenance cost
• Menurut anda, pilihan mana yang terbaik dari ketiga alternatif biaya perbaikan (maintenance cost), dan mengapa pilihan tersebut yang anda pilih.
• Diskusikan dalam kelompok dan kemudian dipresentasikan pada pertemuan berikutnya
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