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Friday 7 September 2012

CHAPTER 3 : MASTER PRODUCTION SCHEDULING (MPS)

Chapter yang seterusnya ialah chapter 3 yang akan membincangkan tenteng Master Production Schedule (MPS).

MPS is a vital link in production planning system that:

  • forms link between production planning and what will actually build.
  • forms basics calculating capacity and resources needed.
  • drive material requirements plan.
  • keeps priorities valid. It also a priority plan for manufacturing.
The information that needed to develop this MPS is:
1) production plan
2) forecasts for individual end items
3) actual orders received from customers and for stock replenishment
4) Inventory levels for individual end items
5) capacity restraints

The objectives in developing an MPS are:
  • to maintain desired level of customer service by maintaining finished goods inventory level or scheduling to meet customer delivery requirement
  • to make the best use of material, labor, and equipment
  • to maintain inventory investment at the required level
PROBLEMS

1) 
Opening Inventory = 50 Dozen
Lot Size = 100 Dozen

Week
1
2
3
4
5
6
Total
Forecast
75
50
30
40
70
20
285
PAB      50
(Ending Inventory)
75
25
95
55
85
65
400
MPS (Production)
100
-
100
-
100
-
300


Ending Inventory =  Opening Inventory + Production - demand
             1            = 50 + 100 - 75 = 75
             2            = 75 + 100 - 50 = 125 - 100 = 25
             3            = 25 + 100 - 30 = 95
             4            = 95 + 100 - 40 = 155 -100 = 55
             5            = 55 + 100 - 70 = 85
             6            = 85 + 100 - 20 = 165 -100 = 65

2)
Opening Inventory = 500 Units
Ending Inventory = 300 Units
Production Leveled = 250 per week

Week
1
2
3
4
Total
Forecast
300
350
300
250
1200
PAB          500
450
350
300
300
1400
Production Plan
250
250
250
250
1000


PAB = Opening Inventory + Production - Forecast Demand
   1    = 500 + 250 - 300 = 450
   2    = 450 + 250 - 350 = 350
   3    = 350 + 250 - 300 = 300
   4    = 300 + 250 - 250 = 300

Week
1
2
3
4
Total
Forecast
200
300
100
100
700
PAB         200
250
200
100
250
800
MPS
250
250
-
250
750


PAB = Opening Inventory + Production - Forecast Demand
    1   = 200 + 250 - 200 = 250
    2   = 250 + 250 - 300 = 200
    3   = 200 + 250 - 100 = 350 - 250 = 100
    4   = 100 + 250 - 100 = 250

Week
1
2
3
4
Total
Forecast
100
50
200
150
500
PAB        300
200
150
200
50
600
MPS
-
-
250
-
250


PAB = Opening Inventory + Production - Forecast Demand
    1   = 300 + 250 - 100 = 450 - 250 = 200
    2   = 200 + 250 - 50   = 400 - 250 = 150
    3   = 150 + 250 - 200 = 200
    4   = 200 + 250 - 150 = 300 - 250 = 50

3)
Opening Inventory = 270 Units
Ending Inventory = 150 Units

Production
Quarter
1
2
3
4
Total
Forecast Sales
220
300
200
200
920
PAB        270
250
150
150
150
700
Production Plan
200
200
200
200
800


Total Production = ∑ Forecast Demand + Ending Inventory - Opening Inventory
                          = 920 + 150 - 270 = 800 Units
Average Total Production = 800 / 4 = 200 Units

PAB = Opening Inventory + Production - Forecast Demand
   1    = 270 + 200 - 220 = 250
   2    = 250 + 200 - 300 = 150
   3    = 150 + 200 - 200 = 150
   4    = 150 + 200 - 200 = 150

Mail Box A. Lot size = 200
Quarter
1
2
3
4
Total
Forecast Sales
120
180
100
120
520
PAB            120
0
20
120
0
140
Production Plan
-
200
200
-
400


PAB = Opening Inventory + Production - Forecast Demand
   1   = 120 + 200 - 120 = 200 -200 = 0
   2   = 0     + 200 - 180 = 20
   3   = 20   + 200 - 100 = 120
   4   = 120 + 200 -120 = 200 - 200 = 0

Mail Box B. Lot Size = 200
Quarter
1
2
3
4
Total
Forecast Sales
100
120
100
80
400
PAB            150
250
130
30
150
560
Production Plan
200
-
-
200
400


PAB = Opening Inventory + Production - Forecast Demand
   1    = 150 + 200 - 100 = 250
   2    = 250 + 200 - 120 = 330 - 200 = 130
   3    = 130 + 200 - 100 = 230 - 200 = 30
   4    = 30   + 200 - 80   = 150

Thursday 6 September 2012

Chapter 2: Production Planning System

ok, kali nie kami akan msuk bahagian calculation dalam chapter nie. kalau adik2 semua dh lpe ape formula untuk selesaikan problems dalam bahagian calculation nie, kami provide kan formula supaya adik2 boleh take note ok...
FORMULA:

  • Total production(TP) = ∑Forecast demand + Back order + Ending inventory – Opening inventory
  • Annual Total Production(ATP) =   TP/# of working days @ period
  • Ending inventory = Opening inventory + Production – Forecast demand
  • TP backlog = ∑Forecast demand + Opening backlog – Ending backlog
  • Ending backlog = Opening backlog + Forecast demand - Production
PROBLEM

1) Production Leveling

Opening Inventory = 100cases
Ending Inventory =80cases

Period
1
2
3
4
5
Total
Forecast (Cases)
110
120
130
120
120
600
Production
116
116
116
116
116
580
Ending Inventory
106
102
88
84
80
460

a) how much should be produced each period?
      
      Answer:
      Total Production (TP) = 600+80-100 = 580 cases
      Average Total Production (ATP) = 580/5 = 116 cases

b) What is the ending inventory for each period?

     Answer:
     Ending Inventory = Open Inventory + Production - Demand
              1                =  100 + 116 -110 = 106
              2                = 106 + 116 - 120 = 102
              3                = 102 + 116 - 130 = 88
              4                = 88   + 116 - 120 = 84
              5                = 84   + 116 - 120 = 80

2) 
Opening Inventory = 150 units
Ending Inventory = 250 units

Month
Aug
Sept
Oct
Nov
Dec
Total
Working Days
10
20
15
21
27
93
Forecast Demand
225
230
218
255
274
1202
Planned Production
140
280
210
294
378
1302
Planned   Inventory  150
65
115
107
146
250
683

a) Total Production (TP) = 1202 + 250 - 150 = 1302 units
    Average Total Production (ATP) = 1302 / 93 = 14 units/day
    Production Each Month:
          Aug  = 10 x 14 = 140
          Sept = 20 x 14 = 280
          Oct  = 15 x 14 = 210
          Nov = 21 x 14 = 294
          Dec =  27 x 14 = 378

b) Ending Inventory in each month 
    Ending Inventory = Open Inventory + Production - Demand
           Aug       = 150 + 140 - 225 = 65
           Sept       = 65 + 280 - 230 = 115
           Oct        = 115+ 210 - 218 = 107
           Nov       = 107 + 294 - 255 = 146
           Dec        = 146 + 378 - 274 = 250

3) Backlog
Opening Backlog = 900 units
Backlog is to be reduced = 200 Units

Week
1
2
3
4
5
6
Total
Forecast Demand
600
700
700
700
600
500
3800
Production
750
750
750
750
750
750
4500
Projected Backlog
750
700
650
600
450
200
3350

a) Total Production Backlog = ∑ Forecast Demand + Open Backlog - Ending Backlog
                                            = 3800 + 900 - 200
                                            = 4500 Units
    ATP Backlog                   = 4500 / 6 = 750 Units

b) Ending Backlog = Opening Backlog + Forecast Demand - Production
                1           = 900 + 600 - 750 = 750
                2           = 750 + 700 - 750 = 700
                3           = 700 + 700 - 750 = 650
                4           = 650 + 700 - 750 = 600
                5           = 600 + 600 - 750 = 450
                6           = 450 + 500 - 750 = 200