Changes to case 2.

cases/case_2/case_2_description.md

@@ -7,17 +7,17 @@ manufacturing and supply chain organization of Beanie Limited in Europe and
 reports directly to Beanie Limited's CEO.
 
 Given Charles role, he gets involved in larger, strategical and long-term
-decisions when we compare with Elisa. One of the hot topics that is currently
-in Charles mind is the next plan for coffee beans reception in European docks.
-Charles' office has reached out to you to prepare a report to assist in this
-highly important decision by using optimisation techniques.
+decisions when we compare with Elisa's domain. One of the hot topics that is
+currently in Charles mind is the next plan for coffee beans reception in
+European docks. Charles' office has reached out to you to prepare a report to
+assist in this highly important decision by using optimisation techniques.
 
-As you are probably aware, coffee beans are not grown in Europe. World
+As you are probably aware of, coffee beans are not grown in Europe. World
 production is divided across South/Central America, Africa and South East Asia.
 Beanie Limited purchases all of its coffee beans from different providers in
 America, mainly in Brasil and Colombia (these two countries account for almost
 40% of the world production). Beanie Limited procurement teams execute
-purchases with local providers at hose locations and then the coffee beans are
+purchases with local providers at those locations and then the coffee beans are
 shipped in container cargo ships to European docks.
 
 Docks are a natural bottleneck in supply chains. Dock capacity in europe is
@@ -47,7 +47,7 @@ Europe:
 - Valencia
 - Genoa
 
-In the upcoming months, Charles team must sign contracts with some of these
+In the upcoming months, Charles' team must sign contracts with some of these
 docks to ensure incoming capacity for the coffee beans coming from America.
 This means they will agree with the docks on the expected handled volumes and
 thus they must decide with which docks they want to work and how much volume
@@ -75,6 +75,9 @@ costs are as low as possible.
 - You need to use a Python notebook to solve all levels. A helper notebook is
   provided. Please attach a notebook that shows your
   solution/proposal/analysis.
+- For the areas of the report where you have built an optimization model,
+  please provide a formal definition of the problem in mathematical terms. This
+  sould include the target function, decision variables and constraints.
 - Include your team number, names and student IDs in all your deliverables.
 
 ## Data
@@ -84,70 +87,106 @@ A few facts:
 - Charles' team estimates that Beanie Limited will need to receive 1,500,000
   metric tons of coffee beans in European docks during next year.
 - The category being negotiated is 40 feet containers. 40 feet containers have
-  a a capacity of 66 cubic meters.
+  a capacity of 66 cubic meters.
 - One cubic meter of coffee beans weights approximately 450 kgrs.
 
-Charles' team has shared with you a table with the prices proposed by the
-different docks for 40ft containers. You can also find the maximum capacity
-that the dock is willing to provide to Beanie Limited (the capacity is
-described as a count of 40ft containers).
+Charles' team has shared with you a table (prices_and_capacities.csv) with the
+next year's prices proposed by the different docks for 40ft containers. You can
+also find the maximum capacity that the dock is willing to provide to Beanie
+Limited (the capacity is described as a count of 40ft containers).
+
+## Notebook
+
+A notebook with some helping code has been provided. The code contains examples
+on how to use `pulp`, a python package for modeling and solving optimization
+problems. You can use it to get familiar with how to solve linear, integer and
+mixed programming problems.
 
 ## Levels
 
-Level 1
+### Level 1
 
 Examine the data provided below and current proposals data. Do you think there
-is a chance to reduce costs? Why?
+is a chance to reduce costs? Why? And will next year's total cost lower?
 
 You can assume that last year, around 80% of Beanie Limited's containers
 entered through Rotterdam and the remaining 20% through Amsterdam. Total volume
-was around 34000 40ft containers.
+was around 24000 40ft containers. Although they don't have more granular
+numbers at hand, Charles mentioned that they had a total expense of 13,700,00€
+on docks fees.
 
-Level 2
+### Level 2
 
 With the price and capacity data provided for each dock, Charles would like you
 to find out what is the optimal distribution across the different options for
 next year. He is expecting you to provide the exact numbers, as well as the
 expected costs that would result from your proposal.
 
-Level 3
+### Level 3
 
 As it tends to be in these projects, sometimes new information appears in the
 middle of the project. Charles' team has reached out to let you know that they
-have some additional details from the different ports. The following docks have
-a sign-up fee. This means that, if Beanie Limited wants to do any business with
-them at all, they need to pay this fee. This fee is only paid once and is
-independent of the container volume that goes through the dock.
+have some additional details from the different ports.
+
+The following docks have a sign-up fee. This means that, if Beanie Limited
+wants to do any business with them at all, they need to pay this fee. This fee
+is only paid once and is independent of the container volume that goes through
+the dock.
 
 - Algeciras: 800,000€
 - Marseille: 500,000€
 - Antwerp: 1,000,000€
 
+Also, after presenting your initial results from level 2, Charles is very happy
+with your work, although there is something bothering him. Even though your
+proposal sounds reasonable, he is concerned that splitting the operations
+between too many docks might make land logistics operations too complex and end
+up causing higher costs in their truck transportation that cancel the potential
+savings that could be obtained in docks operations.
+
+Charles doesn't have numbers currently, so there is no way to tackle this
+properly in an empirical way. To have the necessary information to think about
+this in the future, he would like you to repeat your analysis with a new
+condition in place: to only use a maximum of 3 docks in your proposal. Charles
+wants to know what would be the optimal decision while restricting the used
+docks to that number.
+
 Charles wants you to reassess the situation with the new data and provide the
 adequate solution with the new options. He also would like to understand how
 these changes impact the solution you provided for level 2 and the overall
 results for Beanie Limited.
 
-Level 4
+### Level 4
 
-After presenting your results from level 3, Charles is very happy with your
-work, although there is something bothering him. Even though your proposal
-sounds reasonable, he is concerned that splitting the operations between too
-many docks might make European land logistics operations too complex and end up
-causing higher costs in their truck transportation that cancel the potential
-savings that cana be obtained in docks operations.
+Now that it seemed you finally had a proper proposal in place, Charles is
+calling again with more concerns and asking you to go the extra mile with a
+final assessment.
 
-Charles doesn't have numbers currently, so there is no way to tackle this
-properly. To have the necessary information to think about this in the future,
-he would like you to repeat your analysis with a new condition in place: to
-only use a maximum of 3 docks in your proposal. Charles wants to know what
-would be the optimal decision while restricting the used docks to that number.
+Apparently, some rumours have reached Charles ears. It seems that some new
+regulations in Spain might affect taxes related to dock activities. Charles
+believes this could have an impact on the prices in Valencia and Algeciras,
+putting pressure on them to increase their prices because additional taxes
+would increase their own costs. The issue is: Charles doesn't know for sure
+what will happen. His expert opinion is that the following is possible:
 
-Finally, to spice things up, one of the analysts in Charles' team also calls
-you to inform that the management from the Rotterdam docks has warned Beanie
-Limited that they have a new minimum volume policy in place. They will only
-make business with Beanie Limited if they commit to handle, at least, 30000
-thousand containers through Rotterdam.
+- For Valencia, Charles thinks the price can end up somewhere between today's
+  price (310€/40ft) and 390€/40ft. He says the probability of any price is in
+  that range is equal.
+- For Algeciras, Charles thinks the price can end up somewhere between today's
+  price (280€/40ft) and 330€/40ft. Again, he says the probability of any price
+  is in that range is equal.
+
+Charles heard you did a great job by using simulation techniques with Elisa in
+your previous project. Charles' can't request you to do any simulation work as
+part of the current engagement, because that would be out of the scoped that
+was agreed upon. But nevertheless, he would appreciate if you could explain to
+him how would you use simulation to make the decision with these new
+uncertainty in place. What would be your methodology? What kind of results
+could you provide to him?
+
+With that information, he might decide to spend some more money with Simiupf to
+pursue that stream of work. And that would definetely make your bosses very
+happy!