Jumat, 12 Mei 2017

Soal dan Pembahasan Maintenance Costing

Kerjakanlah soal – soal maintenance costing berikut ini !!
1.      To Calculate the mean time to repair (MTTR ) ?
a.       Eight Subsytem : a, b, c, d, e, f, g, h form an electronic system.
b.      The constants failure rates of these subsystems are :
la = 0.002 , lb = 0.004 , lc = 0.006 , ld = 0.008 , le = 0.010 , lf = 0.012 , lg = 0.014 , lh = 0.016 failures per hour.
c.       The corresponding estimate corrective maintenance time are :
Ta = 2 hour, Tb =  3 hour, Tc = 4 hour, Td = 5 hour, Te = 6 hour, Tf = 7 hour, Tg = 8 hour, Th = 9 hour.

Jawaban :      

§  Diketahui
ada 8 sub system yang membentuk elektronik system dengan tingkat konstanta kegagalan sub system ini :
la = 0.002 , lb = 0.004 , lc = 0.006 , ld = 0.008 , le = 0.010 , lf = 0.012 , lg = 0.014 , lh = 0.016 failures per hour.
Dengan estimasi waktunya :

Ta = 2 hour, Tb =  3 hour, Tc = 4 hour, Td = 5 hour, Te = 6 hour, Tf = 7 hour, Tg = 8 hour, Th = 9 hour.
2.      Data historical of machine in industry :
a.       Hour ( 0 to 200) = up-time
b.      Hour ( 200 to 210 ) = down-time
c.       Hour ( 210 to 400 ) = up-time
d.      Hour ( 400 to 415) = down-time
e.       Hour ( 415 to 590 ) = up-time
f.       Hour ( 590 to 600 ) = down-time
g.      Hour (600 to 750 ) = up-time

To calculate of :
·  the mean time to between failure (MTBF ) and mean downtime (MDT) ?
·   the annual labor cost of corrective maintenance (CMal) ?
Whereas : SOH = 3500 hour, MTTR = 30 h, LCH = $ 40.
          Jawaban :
Diketahui :  
Data historical of machine in industry :
a.       Hour ( 0 to 200) = up-time
b.      Hour ( 200 to 210 ) = down-time
c.       Hour ( 210 to 400 ) = up-time
d.      Hour ( 400 to 415) = down-time
e.       Hour ( 415 to 590 ) = up-time
f.       Hour ( 590 to 600 ) = down-time
g.       Hour (600 to 750 ) = up-time
Ditanya :
a)      the mean time to between failure (MTBF ) and mean downtime (MDT) ?
b)      the annual labor cost of corrective maintenance (CMal) ?
Whereas : SOH = 3500 hour, MTTR = 30 h, LCH = $ 40.

Jawab : 
3.      Maintenance Cost-Related Data :
Description
Manufacture A system
Manufacture B system
Manufacture C System
Expected Life
15 years
15 years
15 years
Expected cost of  a corrective maintenance action
$2000
$2500
$3500
Annual failure rate
3 failures per year
3.5 failures per year
2.5 failures per year
Annual interest rate
4 %
4 %
4 %
Determine which of the three system will be less costly with present value of corrective maintenance ( Find the value of (PV)?
NB : Using the Formula II.

Jawaban :

4.      Assume that we have the following time estimates to accomplish an activity :
OT = 85 days
PT = 105 days
MT = 90 days
To Calculate the activity expected duration time  ( Ta )?

Jawaban : 

5.      Assume that in maintenance organization we have the following data :
TAH = 2500 hour
BR = 0.2
LR = $25
N  = 50
To Calculate the cost per employee (Cem)and The total labor cost ( TLC )?
          Jawaban :
§ Cem =  25 (1 + 0.2) 2500
                    
                    =   $75,000
      

  •   TLC =  $75,000 x 50

                     =    $3,750,000