CaseStudyForm
Title The American Steel Planning Problem
DateSubmitted 30 Apr 2008
CaseStudyType TeachingCaseStudy
OperationsResearchTopics LinearProgramming, IntegerProgramming, NetworkOptimisation, TransshipmentProblem
ApplicationAreas Logistics
ProblemDescription American Steel, an Ohio-based steel manufacturing company, produces steel at its two steel mills located at Youngstown and Pittsburgh. The company distributes finished steel to its retail customers through the distribution network of regional and field warehouses shown below:

The network represents shipment of finished steel from American Steel's two steel mills located at Youngstown (node 1) and Pittsburgh (node 2) to their field warehouses at Albany, Houston, Tempe, and Gary (nodes 6, 7, 8 and 9) through three regional warehouses located at Cincinnati, Kansas City, and Chicago (nodes 3, 4 and 5). Also, some field warehouses can be directly supplied from the steel mills.

Table 1 presents the minimum and maximum flow amounts of steel that may be shipped between different cities along with the cost per 1000 ton/month of shipping the steel. For example, the shipment from Youngstown to Kansas City is contracted out to a railroad company with a minimal shipping clause of 1000 tons/month. However, the railroad cannot ship more then 5000 tons/month due the shortage of rail cars.

Table 1 Arc Costs and Limits | From node | To node | Cost | Minimum | Maximum | | Youngstown | Albany | 500 | - | 1000 | | Youngstown | Cincinnati | 350 | - | 3000 | | Youngstown | Kansas City | 450 | 1000 | 5000 | | Youngstown | Chicago | 375 | - | 5000 | | Pittsburgh | Cincinnati | 350 | - | 2000 | | Pittsburgh | Kansas City | 450 | 2000 | 3000 | | Pittsburgh | Chicago | 400 | - | 4000 | | Pittsburgh | Gary | 450 | - | 2000 | | Cincinnati | Albany | 350 | 1000 | 5000 | | Cincinnati | Houston | 550 | - | 6000 | | Kansas City | Houston | 375 | - | 4000 | | Kansas City | Tempe | 650 | - | 4000 | | Chicago | Tempe | 600 | - | 2000 | | Chicago | Gary | 120 | - | 4000 |

The current monthly demand at American Steel's four field warehouses is shown in Table 2.

Table 2 Monthly Demands

| Field Warehouses | Monthly Demand | | Albany, N.Y. | 3000 | | Houston | 7000 | | Tempe | 4000 | | Gary | 6000 |

The Youngstown and Pittsburgh mills can produce up to 10,000 tons and 15,000 tons of steel per month, respectively. The management wants to know the least cost monthly shipment plan.

ProblemFormulation The formulation...
ComputationalModel The computational model...
Results The results...
Conclusions In conclusion...
ExtraForExperts

StudentTasks

Edit | Attach | Watch | Print version | History: r8 < r7 < r6 < r5 < r4 | Backlinks | View topic | Raw edit | More topic actions...
Topic revision: r5 - 2008-04-29 - MichaelOSullivan
 
  • Edit
  • Attach
This site is powered by the TWiki collaboration platform Powered by PerlCopyright © 2008-2025 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback