"BEST-OF-BREED"
INTEGRATION DEPENDS ON THE ARCHITECTURE OF THE MRP HOST
There are normally
three different ways to integrate the configured pegged demands with
the host:
Least Modification
of a Legacy MRP System
A majority of host
MRP vendors choose to take the path of least resistance to a bolt-on
configuration solution (and often the same with their own internal
configurator module). They require establishment or an upload of a
unique item master for hard or onetime B/M structures and routings.
With these hard onetime structures in place, normal MRP batch
functionality can continue for cost buildups, requirements
planning, WIP allocation, and shop paper release processing.
The obvious
disadvantage of this technique is that it continually builds up hard
assembly structures and routings that are of little further use,
requiring excessive upload, maintenance, and low-level code
continuity processing. It also forces the CTP planning into batched
net-change cycles typical of stocked forecasted products. This,
however, is not responsive enough for to-order CTP scheduling. The
structuring of multilevel MRP netting is complicated by the use of
pseudos and phantoms, requiring still more item masters. Front-end
sales configurators that merely claim to somehow "pitch" their
transactions to the MRP host often leave this huge gap that can
become a disastrous oversight.
Direct Uploading of Mfg-Orders
Only a few MRP
systems, normally those emanating from a job-shop architecture,
provide direct input of M/O material allocations and routing
operations without the need for a hard part number item master
preloaded for each sales order line item. Some of these MRP systems
were specifically designed to anchor the M/O directly from the sales
order line-item file. Careful attention, however, needs to be given
to time-phased allocation logic, whereby allocations are often
merely stacked up in a current bucket balance. Provision also needs
to be made to build cost-of-sales for invoicing from only the M/O
records. The advantage of this host architecture is that files do
not build up with hard onetime structures, since no hard I/M, B/M,
or routing records need to be loaded and subsequently maintained.
If the Company Is
Progressing Toward Mass Customization, Simplification, and a FLOW
Focused Factory Plant Layout, a Completely Fresh Approach Is Now
Available to Achieve Desired Cycle Time Reduction
See figure 3. For product families that are built-to-order in these
FLOW Focused Factories, simplification of scheduling and control
paperwork is a major objective. For example, labor reporting by part
or order number becomes a non-value-added activity where products
are mix-scheduled within a family line. Feedback reporting
transactions, even though bar-coding may be employed, is also a
non-value-added activity. Most component material will be consumed
from line stock and visually replenished using kanban.
Even though most
component material is JIT stocked (figure 4) and consumed on the
line, satisfactory accounting measurement of labor performance and
material usage variances are still supported with timely and
accurate charge-off (backfiushed) transactions. These are now
summarized by the configurator and uploaded asynchronously to the
host (often material usage as a simplistic component unplanned
issue). If the configurator has generated the routing standards and
has the downloaded component costs, then current cost-of-sales
values are built on the fly and included in the sales order
line-item transaction records. At billing time, the host system
merely applies the COS from the uploaded SOE record. It eliminates
the need for a batched rolled-up COS posted to a onetime unique item
master for each line-item. Of course, uploading and maintenance of
the attendant MRP B/M-Rtg records required to generate the COS is
completely eliminated.
SHOP FLOOR
INSTRUCTIONS AND COMPONENT PLANNING IS CONFIGURATOR-DRIVEN
Shop floor parts
lists, manufacturing instructions (routings), and rule-based
operator sequences are "broadcast" directly to the FLOW Focused
Factory cells from the configurator. They had been scheduled under
CTP control and sequenced for setup considerations with selectable
attributes by production management. The objective is to have not
more than several hours of paperwork committed (printed) in any
cell. This is the most effective and simplistic way possible to
facilitate unprecedented rescheduling flexibility and status
feedback. There is little need to develop and maintain a WIP file
(in to-order FLOW Focused Factories), which are otherwise normally
required to support an unnecessary and non-value-added cumbersome
batch ERP functionality.
Many users and
practitioners, after experiencing results with simplified
configure-to-order FLOW Focused Factories, are seriously
questioning the relevance of bolt-on ERP enhancers such as advanced
planners (APS), planning B/M forecasting, fast exploders, finite
loaders, supply chain optimizers, and bar-coded labor feedback
execution systems (MES). They are proving to be of little
value-added in short cycle "to-order" FLOW Focused Factories that
have drastically reduced their backlogs. These symptom solving
systems all depend upon B/M-Rtg's and WIP files, which are being
simplified out of existence! They are being replaced by an
industrial-strength configurator that, by itself, internally
performs costing, promising, scheduling, and sequencing for FLOW
Focused Factories!
If, however, the
total manufacturing cycle time remains extensive (even after
simplification efforts relating to complexity of the product), the
use of more sophisticated advanced planners (APS) may be
warranted—fed directly from the configurator's material and load
demand file. The configurator then relegates to event-driven
customer promising with online real-time (re)calculations of
rough-cut availability commitments prior to frequent batch runs of
the advanced planner. In any case, the configurator alerts the
order entry planning function to abnormal peak overloads that the
flow-line or kanban order-point replenishment strategy might not be
able to cover!
If forecasting of
longer lead time purchased or fabricated in-house componentry is
still required, bottom-up rules can be used to automatically
develop feature percentage planning multipliers. A major advantage
lies in the capability to generate selected commodity forecasts on
an inquiry basis as needed to support direct vendor scheduling and
purchasing negotiations.
To Be Continued
For balance of this article, click on the below link:
Lean Manufacturing Articles and go to Series 01