Category: Manufacturing
Title: Building a custom machine out of Lego bricks

When building a custom machine out of Lego bricks, you first need to
develop the basic design. After that, you order certain Lego brick sets. 
You give the lego sets to a group of children which should sort the parts for you (into a
number of containers). Your machine is built out of a number of subcomponents.
You build them individually, using parts from the sorted containers.  If there
are no more parts in a container, you reorder individual parts. After building
each subcomponent, you have to test them individually and (if each test is
successful) assemble them. If subcomponents are not tested successfully, you have
to redesign and rebuild them.