HI,

 Just to return to this topic.

Comment has been passed on the Toyota production System being the best 
combination of local and central control.

I passed the message to a friend of mine in the motor industry and he 
replied with this detailed insight (permission for circulation given):

Hello Ceri,

Yes, I broadly agree that the Toyota way has a good balance between 
central and local control but the principles of TPS are the drivers.

What is interesting though is that initially on set up of a 
'transplant', there is more control and less flexibility at outset to 
let things bed in. As confidence in the process and its system support 
grows, the level of flexibility and complexity of product handled 
increases - so what might be a single specialised product production 
line will become multi-product and spec over time.

In as much as the key factor is customer pull, with a goal of little or 
no inventory throughout the process, and the build of component or 
finished product is only put in place when an order is placed, the 
control starts with the external customer with the appropriate internal 
customers pulling the component of the order as and when it is needed at 
the point it is actually required in the process to allow the order to 
be completed through the process on time.

Much of the quality aspect is down to design and assembly capability of 
the components backed up with the emphasis on little or no stock (so if 
there is a problem it is recognised up front by the operator working on 
specific componentry rather than hidden in a stock whose traceability is 
difficult once it is incorporated in the finished product). A important 
point here is that there must be a high level of trust as well as SPC to 
stop the line if there is a problem before it gets out of hand - such 
responsibility has to work at the operator level.

Another important factor is that Toyota are less worried about capacity 
utilisation - once the line is in it is treated as 'sunk cost' - and, if 
it is not running at full pelt, then there is spare capacity - rather 
than the Fordist way of needing to keep the process running and plant 
utilised regardless of demand pull (hence the difference between mass 
production and marketing and customised production etc.

Whilst the Honda way is similarly lean - there is much more central 
control and rigidity in the process with long stable runs of production, 
batches (rather than TPS's batch on one) which must be adhered to at all 
costs. Honda is a modern version of Ford (low variety, high capital 
utilisation, efficient production - so leanness in plant is ok but is 
sometimes a problem in distribution.

---------------------------
Regards,

Ceri