Page 135 - How To Implement Lean Manufacturing

114 Cha pte r Se v e n

Tools Used
• Balancing is done by completing the basic time study and then designing the
work at each work station to be the same. Normally, some accommodation is
made for OEE (Overall Equipment Effectiveness) to account for pro duction
losses caused by availability issues, quality dropout, and cycle-time losses. The
end result of balancing should be work stations that are synchronized.
• Standard work is the technique used to review the performance, including the
cycle time of a production process, production cell, or a production work station.
It is a key tool in evaluating and assisting the production process to achieve
synchronized production.

Wastes Reduced
Waiting is the key waste removed, and while inventory is often reduced, the goal is
one-piece flow.

Summary of Synchronize Internally
The key tool used to synchronize internally is the basic time study coupled with the
balancing study and chart. The balancing chart will show at a glance three major aspects
of the process.

• The relative cycle times of each step: the balance
• The waste of waiting due to the imbalance
• The process bottleneck
From this balancing chart, the work begins and is comprised of two major steps.
First, the production cycle time must be calculated. It is normally the takt time multi-
plied by the actual OEE, if that is known. So if takt is seven minutes and OEE is 0.80 or
80 percent, the cycle time of the process will need to be 5.6 minutes. With this known, it
is now time for the second task, which is to design all work stations to have a 5.6 minute
cycle time. With these two steps we have balanced the process steps (synchronized
internally) to a production cycle time that will achieve takt (synchronized externally).
To synchronize the process internally, always create a huge to-do list.
In the application of this strategy, it is best to go to the end of the value stream and
work backwards, as much as practical. For example, if there are three work cells in
series that comprise the value stream, work on the cell closest to the storehouse first.
This order, of starting at the customer and working backwards in the flow, should also
be employed with the following two strategies of creating flow and installing pull-
demand systems.

Strategy 3: Create Flow

Conceptual Discussion
The concept of flow is such that we do not want the production units to stop, except for
value-added work. The flow concept has both overall measures and local measures.
The local measure would be cycle time. That is the increment of time between consecu-
tive production units. If work is done, one piece at a time, it is also the processing time