The wastes of Lean

Looking for waste at your bottleneck? This checklist might help you:

• Overproduction
  Overproduction is everything you do too much. It will probably increase your inventory of something without benefit for the whole company. Instead it will probably create more waste as the inventory increases, because the "warehouse" will need its own management.
  Overproduction reduces agility and increases operational cost without increasing the throughput of value.
• Unprocessed inventory
  Inventory that is not immediately processed is or should be mostly unnecessery. Hereby remember that your bottleneck has to have a buffer. Maybe you will even need multiple buffers throughout the system to ensure that the flow of work can continue in every situation. But generally you want your inventory to be small, because having it costs resources without giving the organisation any benefit.
• Motion
  If what you need to do could be achieved with less effort, go for it.
• Defects
  Defects create rework. Try to create processes and techniques to avoid them in the first place.
• Over-processing
  Over-processing can be translated into YAGNI. Whenever doing things that are not needed to bring benefit to the customer, you over-process.
• Waiting
  Waiting introduces an interesting problem. First, people forget. Thus, the longer the waiting time the more information about a task is lost. That might be regained (by reading things up) but it will take longer. But it also might be just lost.
  E.g. the longer the time between task completion and review, the more likely it is that problems escape the quality assurance.
  Second, waiting time reduces the value the customer gets out of his investment. Consider the difference it makes to purchase an item and have a one week delivery compared to purchasing an item and getting it delivered instantly.
  Again, not all waiting times are equal. E.g. in the Theory of Constraints it is very important that the bottleneck is not waiting for anything, while the non-constraint resources of course will not be used to their full capacity and thus will be waiting every now and then.
• Transport
  Most of the time the transport of an object does not add to its value. If it does not then try to remove the transportation.
  A person that did this famously is Henry Ford with his assembly line and rearrangement of the manufacturing floor.