兰州大学运筹学 - 线性规划在管理中的应用 课后习题题解

内容发布更新时间 : 2024/11/15 2:07:41星期一 下面是文章的全部内容请认真阅读。

x56≤15000 x57≤15000 x58≤15000 x59≤15000 x60≤15000

0.2 x25+0.4 x37- x49=0 0.2 x26+0.4 x38- x50=0 0.2 x27+0.4 x39- x51=0 0.2 x28+0.4 x40- x52=0 0.2 x29+0.4 x41- x53=0 0.2 x30+0.4 x42- x54=0 0.2 x31+0.4 x43- x55=0 0.2 x32+0.4 x44- x56=0 0.2 x33+0.4 x45- x57=0 0.2 x34+0.4 x46- x58=0 0.2 x35+0.4 x47- x59=0 0.2 x36+0.4 x48- x60=0 x i≥0 i=1-60

(这是一个60个变量,60个约束条件的纯属规划数学模型,求解时需要扩充求解模板)。 见《第五章习题61.xls》求解结果是“找不到有用的解”。其原因是后三个月每月都需要两种产品总和150千件,而每月两种产品的总产量只有120千件,所以必须要有90千件产品要有9月份前做好储备,而90件的最小体积为18000m3,而库房只15000m3,所以该问题就无法安排了,所以系统就找不到有用的解了。

2、为了后几个月每月较大的需求量,就需要向外厂租借仓库,以补本厂库容不足的要求。这样就需要对外借仓库容量与本厂仓库容量和需求一同考虑。

(1)确定决策变量

我们将考虑外借仓库后,问题的关系整理如下表: 月份 1 2 10 5 x2 3 10 5 x3 4 10 5 x4 5 30 5 x5 6 30 4.5 x6 7 30 4.5 x7 8 30 4.5 x8 9 30 4.5 x9 10 100 4.5 x10 11 100 4.5 x11 12 100 4.5 x12 仓容 外存 销售量(千件) 10 成本(元、件) 5 产 产量(件) Ⅰ 库存数 x1 3品 总容积(千m) 0.2x1 0.2x2 0.2x3 0.2x4 0.2x5 0.2x6 0.2x7 0.2x8 0.2x9 0.2x10 0.2x11 0.2x12 x2+ x3+ x4+ x5+ x6+ x7+ x8+ x9+ x10+ x11+ x12+ x1-10 x25-10 x26-10 x27-10 x28-30 x29-30 x30-30 x31-30 x32-30 x33-100 x34-100 x35-100 1500050 8 x14 15 8 x15 15 8 x16 15 8 x17 15 7 x18 15 7 x19 15 7 x20 15 7 x21 50 7 x22 50 7 x23 50 (m3) 7 3x24 1元/m x25= x26= x27= x28= x29= x30= x31= x32= x33= x34= x35= x36= 容量 不限 1.5元/m3 销售量(千件) 50 成本(元、件) 8 产 产量(件) 3x13 品 总容积(千m) 0.4x13 0.4x14 0.4x15 0.4x16 0.4x17 0.4x18 0.4x19 0.4x20 0.4x21 0.4x22 0.4x23 0.4x24 Ⅱ 库存数 x37= x38= x39= x40= x41= x42= x43= x44= x45= x46= x47= x48= x14+ x15+ x16+ x17+ x18+ x19+ x20+ x21+ x22+ x23+ x24+ x13-50 x37-50 x38-15 x39-15 x40-15 x41-15 x42-15 x43-15 x44-15 x45-50 x46-50 x47-50 x50 x51 x52 x53 x54 x55 x56 x57 x58 x59 x60 仓 容 本厂(千m) x49 3 外借(千m) x61 产 品 总和 (千件) 120 3x62 x63 x64 x65 x66 x67 x68 x69 x70 x71 x72 120 120 120 120 120 120 120 120 120 120 120 (2) 确定目标函数

由于考虑了外借仓库,所以要在目标函数中加外借仓库的存储费用。 费用=5×(x1+ x2+ x3+ x4+ x5)+4.5×(x6+ x7+x8+ x9+ x10+ x11+ x12)+8×(x13+ x14+ x15+ x16+ x17)+7×(x18+ x19+x20+ x21+ x22+ x23+ x24)+(x49+ x50+x51+ x52+ x53+ x54+ x55+ x56+ x57+ x58+ x59+ x60)+1.5×(x61+ x62+x63+ x64+ x65+ x66+ x67+ x68+ x69+ x70+ x71+ x72)

所以目标函数为: min f=5×(x1+ x2+ x3+ x4+ x5)+4.5×(x6+ x7+x8+ x9+ x10+ x11+ x12)+8×(x13+ x14+ x15+ x16+ x17)+7×(x18+ x19+x20+ x21+ x22+ x23+ x24)+(x49+ x50+x51+ x52+ x53+ x54+ x55+ x56+ x57+ x58+ x59+ x60)+1.5×(x61+ x62+x63+ x64+ x65+ x66+ x67+ x68+ x69+ x70+ x71+ x72)

(3)确定约束条件

考虑了外借仓库后,其约束条件就只对仓容与库存量关系加上外借仓容部分。 仓容与库存量关系(m3): 0.2 x25+0.4 x37= x49+ x61 0.2 x26+0.4 x38= x50+ x62 0.2 x27+0.4 x39= x51+ x63 0.2 x28+0.4 x40= x52+ x64 0.2 x29+0.4 x41= x53+ x65 0.2 x30+0.4 x42= x54+ x66 0.2 x31+0.4 x43= x55+ x67 0.2 x32+0.4 x44= x56+ x68 0.2 x33+0.4 x45= x57+ x69 0.2 x34+0.4 x46= x58+ x70 0.2 x35+0.4 x47= x59+ x71 0.2 x36+0.4 x48= x60+ x72

其它部分都与前面的完全相同。

因此可得本问题的线性规划数学模型:

Min f=5×(x1+ x2+ x3+ x4+ x5)+4.5×(x6+ x7+x8+ x9+ x10+ x11+ x12)+8×(x13+ x14+ x15+ x16+ x17)+7×(x18+ x19+x20+ x21+ x22+ x23+ x24)+(x49+ x50+x51+ x52+ x53+ x54+ x55+ x56+ x57+ x58+ x59+ x60)+1.5×(x61+ x62+x63+ x64+ x65+ x66+ x67+ x68+ x69+ x70+ x71+ x72)

S.T. x1+ x13≤120000

x2+ x14≤120000 x3+ x15≤120000 x4+ x16≤120000 x5+ x17≤120000 x6+ x18≤120000

x7+ x19≤120000 x8+ x20≤120000 x9+ x21≤120000 x10+ x22≤120000 x11+ x23≤120000 x12+ x24≤120000 x1-x25=10000

x2+ x25-x26=10000 x3+ x26-x27=10000 x4+ x27-x28=10000 x5+ x28-x29=30000 x6+ x29-x30=30000 x7+ x30-x31=30000 x8+ x31-x32=30000 x9+ x32-x33=30000 x10+ x33-x34=100000 x11+ x34-x35=100000 x12+ x35-x36=100000 x13- x37=50000

x14+ x37-x38=50000 x15+ x38-x39=15000 x16+ x39-x40=15000 x17+ x40-x41=15000 x18+ x41-x42=15000 x19+ x42-x43=15000 x20+ x43-x44=15000 x21+ x44-x45=15000 x22+ x45-x46=50000 x23+ x46-x47=50000 x24+ x47-x48=50000 x49≤15000 x50≤15000 x51≤15000 x52≤15000 x53≤15000 x54≤15000 x55≤15000 x56≤15000 x57≤15000 x58≤15000 x59≤15000 x60≤15000

0.2 x25+0.4 x37- x49- x61=0 0.2 x26+0.4 x38- x50- x62=0

0.2 x27+0.4 x39- x51- x63=0 0.2 x28+0.4 x40- x52- x64=0 0.2 x29+0.4 x41- x53- x65=0 0.2 x30+0.4 x42- x54- x66=0 0.2 x31+0.4 x43- x55- x67=0 0.2 x32+0.4 x44- x56- x68=0 0.2 x33+0.4 x45- x57- x69=0 0.2 x34+0.4 x46- x58- x70=0 0.2 x35+0.4 x47- x59- x71=0 0.2 x36+0.4 x48- x60- x72=0 x i≥0 i=1-72

(这是一个72个变量,60个约束条件的纯属规划数学模型,求解时需要扩充求解模板)。 见《第五章习题62.xls》求解结果如下表: 月份 1 2 10 5 3 10 5 4 10 5 5 30 5 6 30 4.5 7 30 4.5 8 30 4.5 9 30 4.5 10 100 4.5 11 100 4.5 12 100 4.5 仓容 外存 销售量(千件) 10 成本(元、件) 5 产 品 产量(件) x1=10 x2=10 x3=10 x4=10 x5=30 x6=30 x7=30 x8=45 x9=105 x10=70 x11=70 x12=70 3Ⅰ 总容积(千m) 0.2x1 0.2x2 0.2x3 0.2x4 0.2x5 0.2x6 0.2x7 0.2x8 0.2x9 0.2x10 0.2x11 0.2x12 库存数 x25=0 x26=0 x27=0 x28=0 x29=0 x30=0 x31=0 x32=15 x33=90 x34=60 x35=30 x36=0 50 8 15 8 15 8 15 8 15 7 15 7 15 7 15 7 50 7 50 7 50 7 15000容量 销售量(千件) 50 成本(元、件) 8 产 不限 品 产量(件) x13=50 x14=50 x15=15 x16=15 x17=15 x18=15 x19=15 x20=15 x21=15 x22=50 x23=50 x24=50 3(m) 3 Ⅱ 总容积(千m) 0.4x13 0.4x14 0.4x15 0.4x16 0.4x17 0.4x18 0.4x19 0.4x20 0.4x21 0.4x22 0.4x23 0.4x24 1.5元库存数 x37=0 x38=0 x39=0 x40=0 x41=0 x42=0 x43=0 x44=0 x45=0 x46=0 x47=0 x48=0 1元/m3 /m3 仓 3本厂(千m) x49=0 x50=0 x51=0 x52=0 x53=0 x54=0 x55=0 x56=3 x57=15 x58=12 x59=6 x60=0 容 外借(千m) x61=0 x62=0 x63=0 x64=0 x65=0 x66=0 x67=0 x68=0 x69=3 x70=0 x71=0 x72=0 产 品 总和 (千件) 120 120 120 120 120 120 120 120 120 120 120 120 3总的生产加储存最少费用为4910500元 外借的库房,在9月份用了3千平方米的容量。

灵敏度分析报告:

可变单元格 单元格 名字 $C$5 $D$5 $E$5 $F$5 $G$5 $H$5

x1 x2 x3 x4 x5 x6

终值

10000 10000 10000 10000 30000 30000

递减成本 目标式系数 允许的增量 允许的减量

0 0 0 0 0 0

5 5 5 5 5 4.5

0 0.2 0 0.2 0.2 0

0.2 0 0.2 0.2 0 0.2

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