• Blue company makes widgets
• Red company makes tools that use Blue company widgets
• Blue company makes two new types of widgets: A and B
• Blue company has a factory to make widgets, and it has two flexible work areas: Welding and Painting
• Welding uses one machine with changeable torches to make the two types of widgets that are supplied to the Painting area
• It takes 4 staff in the Welding unit 22 minutes to align the torches to make widget A or widget B
• After the torches are in place, a new widget can be made every 10 minutes
• Both types of widgets are made of the same steel
• A newly weighted widget B weights 7 pounds and widget A weights 5 pounds
• Welded widgets go to Holding Zone 1 until they can be processed by Painting
• In the Painting area, each widget goes through multiple coats and finishes using different tools depending on the widget type
  • It takes 12 minutes for this process
  • The amount of painting required for widget A is 82% of that required for widget B
• After painting is finished, widgets are stacked and placed in Holding Zone 2 until they are picked up by the Blue company and delivered to the assembly facility
• The painting area must be in continuous production
• Work orders come in one at a time, but orders for the same type of widget have the following random probabilities
  • n = 1: .2
  • n = 2: .4
  • n = 3: .1
  • n = 4: .1
  • n = 5: .2
• There must be a minimum Holding of unfinished widgets between welding and painting
• A single card Kanban system is used to manage inventory
  • 12 cards are assigned to Holding Zone 1
• Torch switching can only occur when it is necessary to prevent production disruption

• Question – How many units of either type of widget is the minimum inventory level that would trigger a switch (assume Holding Zone 1 was completely filled before Painting started)
• Question – Is 12 Kanban the optimal number? Why? Why not?