Case studies

The managing director of a steel plant faces the decision of how much of each raw material to order for the plant for the following month. Due to lower and upper bounds on the amounts of each raw material in a batch and varying amounts of electricity and time consumed for different raw materials, one can't simply use the cheapest raw material. A linear program and the solver optimization function of Excel will provide the optimal amounts that meet the constraints. Interestingly, the best mixture for a batch is not the best mixture for a monthly plan. Shadow prices indicate the value of relaxing constraints. The typical monthly model from a student will be nonlinear, although it can be written as a linear model. This case provides the basis for an introductory class on linear programming and linear versus nonlinear models.

In December 2001, after a six-month process of vying for AT&T's Broadband, the president of cable operator Comcast Corporation, had just received word that Comcast's $72-billion offer had won the auction. Comcast, the cable industry's third-largest operator, would merge with industry leader AT&T Broadband to form a company with more than $20 billion in revenue and an unparalleled distribution (a presence in 22 of the nation's top 25 markets). Now the presidents of both companies began to consider their post-merger integration strategies. What was important and how should they prioritize their activities? How could they get all stakeholders to understand the rationale for the deal and its business goals and excited about the new AT&T Comcast?

In the early months of the 2007-08 financial crises, a loan manager faces a real estate financing decision. Should he approve a bullet structure three-year loan to a longstanding client, a legendary Texan developer? The developer, who near retirement downsized his business, is seeking financing for his only project: residential or commercial development on an attractive piece of land in suburban Houston. The loan manager considers the decision in light of the mortgage market turmoil, seeing commercial projects as safer, but also factoring that the residential market could bring higher returns if the market stabilizes soon. The manager collects the data and asks an analyst to assess the risks; that ultimately requires assessing the economics of both projects from both the bank's and the developer's perspectives. The bank could still change the interest rate on the loan to receive adequate compensation for the risk it carries, but the loan manager knows that doing so will change their long-term client willingness to take on the loan.

The CEO of Embraer, reflects on his company's dramatic ascent to its position as the world's leading regional aircraft manufacturer. Since becoming a private company, Embraer had successfully introduced seven commercial aircraft models to the market, including its latest, the 118-seat EMBRAER 195. Now, he is concerned because Embraer does not know what to expect from Bombardier, Boeing, and Airbus regarding their competitive response to his company's recent attacks on the commercial aircraft market. How would they respond to Embraer's successful launch of its recent family of jets? Would Bombardier really follow through with its launch of the CSeries? Would Airbus and Boeing perceive the latest attacks by Embraer and Bombardier as attacks on its own family of jets? Most importantly, given Embraer's expectations of rivals' future competitive moves, what should it do next to protect its position and influence its competitors' actions?

This case concerns the troubles that Euro Disney experienced from the start. Euro Disney claimed that the major cause of its poor financial performance was the European recession and the strong French franc. The timing of the park's opening could not have been more inopportune. If the recession had been the only cause of Euro Disney's problems, the financial restructuring would only need to carry the park forward to better economic times. Only when Europeans began spending freely again would investors learn the answers to some uncomfortable questions: Was the whole idea of Euro Disney misconceived? Were there other fundamental cultural problems that could inhibit the park's success? Would Euro Disney fail to recover even though other European companies did? And, if so, why was the Disney theme-park concept successful in Japan and not in France?

This case features a prominent antidumping case in the United States against six of its major foreign shrimp suppliers. The case fits well in a discussion and analysis of the (welfare) consequences of protectionism, the basic case for free trade, and the political economy of protectionism.

At the core of this case is a distribution, or sourcing, problem that can be modeled and solved using linear programming (LP). There are also issues of whether to build (a) new plant(s)––and if so, what the capacity should be––and whether to expand or close one or more of the existing plants. These latter issues can be analyzed using a 0/1 LP facility-location model. Alternatively, because the number of options is limited, they can be analyzed using the straight LP model of the distribution problem as a tool to facilitate analysis.

George Lasiter sells special-events T-shirts and must decide how many to order for an upcoming concert. He has high, medium, and low estimates of both concert attendance and the percentage of attendees who will want a shirt. In addition, he has assessed the relative likelihoods of each estimate. The case can be used to introduce or reinforce the fundamental issues surrounding decision making under uncertainty.

Julia Brown, toy buyer for the Hightower Department Stores, has to decide which of three imported stuffed animals will be offered for sale by the 16 Hightower stores during the approaching Christmas shopping season. The case is appropriately used as an introduction to the concepts of least squares and regression analysis. A linear relationship between realized and test-market sales can be used to forecast the sales potential of the three proposed animals, and an explicit treatment of the uncertainty in this forecast is necessary in order to decide how many of each adopted animal to order.

The diamond industry has been subject to significant change. There is increased competition from low-wage countries such as India and China, the concern about blood diamonds, and policy issues affecting the viability of trading diamonds. In this case, we study how Antwerp's dominant position in the diamond trade is being challenged and eroded. The case offers a good opportunity to introduce and discuss comparative advantage and relate it to Heckscher-Ohlin type of trade.