Forecast demand | Cumulative demand | Safety stock @20 per cent forecast | Beginning inventory | Production requirement (fest. + SS – beg. inv.) | |
January | 300 | 300 | 60 | 50 | 300 + 60 – 50 = 310 |
February | 500 | 800 | 100 | 60 | 500 + 100 – 60 = 540 |
March | 400 | 1,200 | 80 | 100 | 400 + 80 – 100 = 380 |
April | 100 | 1,300 | 20 | 80 | 100 + 20 – 80 = 40 |
May | 200 | 1,500 | 40 | 20 | 200 + 40 – 20 = 220 |
June | 300 | 1,800 | 60 | 40 | 300 + 60 – 40 = 320 |
Solution:
Table No. 2
(1) Month | Jan. | Feb. | Mar. | April | May | June | July | Aug. | Sept. | Total |
(2) Forecast | 40 | 25 | 55 | 30 | 30 | 50 | 30 | 60 | 40 | 360 |
(3) Workdays/mo | 22 | 18 | 21 | 22 | 22 | 20 | 21 | 22 | 20 | |
(4) Prod. hr avail. =[3](6 wkrs) (8 hr) |
1056 | 864 | 1008 | 1056 | 1056 | 960 | 1008 | 1056 | 960 | |
(5) Reg.-time prod. [4] 740 hr/unit |
26.4 | 21.6 | 25.2 | 26.4 | 26.4 | 24.0 | 25.2 | 26.4 | 24.0 | |
(6) Units subcon’t (2)-(3) | 13.6 | 3.4 | 29.8 | 3.6 | 3.6 | 26.0 | 4.8 | 33.6 | 16.0 | |
(7) Subcon’t cost (6) (Rs.2,000) |
27,200 | 6,800 | 59,600 | 7,200 | 7,200 | 52,000 | 9,600 | 67,200 | 32.000 | 268,800 |
(8) Reg.-time cost(5) (Rs.1,200) |
31,680 | 25,920 | 30,240 | 31,680 | 31,680 | 28,800 | 30,240 | 31,680 | 28,800 | 270,720 |
The total cost of this plan is Rs. 268,800 + Rs. 270,720 = Rs. 539,520.