Matakuliah
Tahun
Versi
: H0204/ Rekayasa Sistem Komputer
: 2005
: v0 / Revisi 1
Pertemuan 22
Analisis Studi Kasus 2
1
Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
• Menghubungkan antara repair system
dengan discard system
2
Outline Materi
• Studi kasus : Repair versus Discard
Evaluation
3
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.
4
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.
5
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.
6
Studi Kasus 2 :
Repair versus Discard Evaluation
• The summary results for all 15 assemblies are presented in table 22.1
Assembly
Number
Maintenance Status
Repair at
Intermediate
Cost ($)
Repair at
Supplier
Cost ($)
Decision
Discard at
failure Cost
($)
A-1
A-2
A-3
A-4
A-5
A-6
A-7
A-8
A-9
A - 10
A - 11
A - 12
A - 13
A - 14
A - 15
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
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
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
Policy Cost
1,071,267
1,035,612
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
7
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
8