To help
manufacturing companies operate as efficiently as possible, most
modernized firms use what are called manufacturing execution systems
(MES).
These plantwide systems are used to keep track of production
schedules, inventory availability, work in progress and a range of
other operations management-related information flowing to and from
the shop floor.
If implemented correctly, an MES can manage, initiate, respond to
and report on each of the primary production activities of a plant.
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Examples of MES at
Work
A manufacturer of custom-built products improves on-time
delivery:
MESs allow for the tracking of specific customer orders and
materials bills at the unit and component levels. This permits
planners to know exactly where each unit is in the production
cycle and what materials are needed and when. It also allows
companies to reduce the inventory they hold and notify
planners when there are product shortages. In addition, MESs
enable planners to better schedule resources, materials,
testing facilities and delivery infrastructures. Customers can
find out exactly when to expect their products.
Manufacturers manage changes in the production process:
An MES can help companies maintain records of products and
processes by unit, subassembly and lot. At each stage, an MES
helps companies gather information on test results, quality
results, operators in charge and whether the product is being
built in compliance with mandatory requirements. Complete
device and product histories and granular details on how the
product was built allow manufacturers to hone in faster and
more accurately on any required changes or production
rerouting.
A manufacturer that outsources production of components to
contract manufacturers:
Provides traceability of all the parts and subassemblies
supplied by third parties. An MES allows a manufacturer to
keep track of changes.
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For instance, a manufacturer of made-to-order electronic goods
can use an MES to optimize materials availability, labor and
shipping resources by tracking production units, components and
subassemblies from the time the order was placed through delivery.
Decisions on the Shop Floor
Delivering minute-to-minute shop-floor information is vital now
that the Internet is driving more of a build-to-order manufacturing
model, says Bill McSpadden, an analyst at Plant-Wide Research Group
in Billerica, Mass.
As a result, companies that want to deliver on these modules need
to have access to end-to-end decision-making information that drills
down to the shop floor, he adds.
"If you look at the success of companies such as Dell, you see
their front-end Web presence is supported by a back end that goes
all the way into their plant floors," says Josh Greenbaum, an
analyst at Enterprise Application Consulting in Berkeley, Calif.
MESs have been used for several years now - mainly in process
industries - to support key operations management functions ranging
from resource allocation and data acquisition to maintenance
management, quality control, performance analysis, labor management
and even paper reduction.
However, there has been little effort, especially on the part of
discrete manufacturers, to collect and make this kind of plant-floor
information available to plant managers and to enterprise management
systems, analysts say.
"For years, MES was considered a point solution on the factory
floor," says McSpadden.
Indeed, most supply-chain integration efforts have focused
primarily on the deployment of business management applications such
as enterprise resource planning (ERP) and customer relationship
management (CRM) systems without addressing operations management
needs, says Andy Chatha, president of ARC Advisory Group Inc., a
manufacturing consultancy in Dedham, Mass.
It's only by integrating a plant-floor system with the rest of
the enterprise that companies are able to get the kind of holistic
view that's needed to support a build-to-order model, he says.
"There's always been this kind of a dividing line" between
plant-floor systems and the rest of the enterprise, Chatha says.
"ERP vendors don't understand plant-automation vendors and vice
versa," he says.
But that's beginning to change, as reflected by the growing trend
among manufacturers to move to an Internet-enabled business that
emphasizes low inventories, short cycle times and quick order
execution, say experts.
Increasingly, there's a need for a high degree of real-time and
near-real-time flow of information spanning plant-floor operations,
order entry, planning and scheduling, CRM and financial operations.
As a result, MESs are being viewed as the vital missing link for
tying plant-floor information with business management information
provided by applications such as ERP and CRM, McSpadden says.
No Easy Task
Despite the benefits, deploying an MES and hooking up the system
with the rest of the enterprise is no easy task, analysts say.
This is especially true in enterprises with a mix of vendor
platforms and legacy systems, such as an IBM AS/400-based MRP II
system connected with a Digital Equipment Corp. VMS-based
order-procurement system.
Hooking an MES into an enterprisewide system requires very tight
integration between systems that are as varied as order entry
systems, product configurators and planning and control systems, as
well as sales force and delivery systems.
Each software component in an integrated enterprise should not
only interface with the other ones but also share information and
communicate in a common format.
Bridging the Gap
Bridging the gap between the two sides means integrating
software, networks, protocols and languages that often bear little
resemblance to each other and require layers of middleware and
connectivity tools.
"MES systems have to be compatible with the existing environment.
Very often, that environment is a hodge-podge of different systems
that need a lot of integration," Greenbaum says.
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