
=360(件)
每年订货次数=3600/360=10(次)
交货期内的平均每天需要量
=3600/360=10(件)
如果延迟交货1天,则交货期为10+1=11(天),
交货期内的需要量=11×10=110(件),概率为0.25。
如果延迟交货2天,则交货期为10+2=12(天),
交货期内的需要量=12×10=120(件),概率为0.1。
如果延迟交货3天,则交货期为10+3=13(天),
交货期内的需要量=13×10=130(件),概率为0.05。
①保险储备B=0时,再订货点R=10×10=100(件)
S=(110-100)×0.25+(120-100)×0.1+(130-100)×0.05=6(件)
TC(S,B)=6×5×10+0×4=300(元)
②保险储备B=10时,再订货点R=100+10=110(件)
S=(120-110)×0.1+(130-110)×0.05=2(件)
TC(S,B)=2×5×10+10×4=140(元)
③保险储备B=20时,再订货点R=100+20=120(件)
S=(130-120)×0.05=0.5(件)
TC(S,B)=0.5×5×10+20×4=105(元)
④保险储备B=30时,再订货点R=100+30=130(件)
S=0
TC(S,B)=30×4=120(元)
通过比较得出,最合理的保险储备为20件,再订货点为120件。
考虑缺货情况下,外购相关总成本=36720+105=36825(元),等于自制情况下相关总成本36825元。
English answers:
Economic order quantity of external purchase=(2×3600×72/4)
1/2=360(units)
Annual order times=3600/360=10(times)
Average daily demand within delivery period=3600/360=10(units)
If the delivery is delayed for 1 day, then the delivery period is 10+1=11 days, average daily demand within delivery period=11×10=110units, and its probability is0.25. If the delivery is delayed for 2 day, then the delivery period is 10+2=12 days, average daily demand within delivery period=12×10=120units, and its probability is0.1. If the delivery is delayed for 3 day, then the delivery period is 10+3=13 days, average daily demand within delivery period=13×10=130units, and its probability is0.05.
①Insurance reserve at B=0,
Re-order point R=10×10=100units
S=(110-100)×0.25+(120-100)×0.1+(130-100)×0.05=6units
TC(S,B)=6×5×10+0×4=300Yuan
②Insurance reserve at B=10,
Re-order point R=100+10=110 units
S=(120-110)×0.1+(130-110)×0.05=2units
TC(S,B)=2×5×10+10×4=140(Yuan)
③Insurance reserve at B=20,
Re-order point R=100+20=120 units
S=(130-120)×0.05=0.5units
TC(S, B)=0.5×5×10+20×4=105(Yuan)
④Insurance reserve at B=30,
Re-order point R=100+30=130units
S=0
TC(S, B)=30×4=120(Yuan)
The most reasonable insurance reserve is 20 and re-order point is 120 through comparison. If the circumstance of out of stock is considered, cost related to external purchase=36720+105=36825(Yuan)which is equal to the cost of self production.