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Modern Maschine
Shop (November 2002, page 78-83)
Emphasis: Sytems & Software
Integrated Tool Management Bridging the gap between process engineering and shop floor activities
can bring about a "deproliferation” of cutting tools.
By Goetz Marczinski,
Cimsource
In general, cutting tools account for about 3 to 5 percent of total
manufacturing cost. By itself, this level of expense may not be enough
to attract the attention of top management at major manufacturing companies.
However, activity-based costing has tended to reveal that the cost involved
in the sourcing and replenishment process can exceed the purchase value
of tools-an insight that has led many manufacturers to switch to full-service
supply. Also, there is the painful irony that even though $50,000 worth
of cutting tools may be tied up per manufacturing line or flexible cell,
stock-outs are still a recurring problem. Many facilities have looked
to shopfloor tool management to help address this problem.
But there is only so much that can be done at the shopfloor level.
To look to the shop floor for the solution to these problems is to take
for granted the tool as it was released from engineering, and treat
tool management as merely a logistics and delivery challenge. The flaw
in this thinking is revealed when one considers the sources of the inefficiencies
that the shop floor confronts. These sources include...
- The large number of distinct components the shop floor
must manage.
- The variety of obviously redundant tooling from multiple
sources.
- The differing tool layouts.
- The error-prone nature of entering tool data into shopfloor
systems.
What this list suggests is that many of the decisions affecting the
difficulty of tool management have already been made before any physical
tool comes into play. In fact, close to 70 percent of the difficulty
in shopfloor tool management is created in engineering. Here the tool
layout is fixed, and so are the supplier and the operation. Thus 70
percent of the life cycle cost of the tooling is fixed as well.
A concept called integrated tool management allows for the fact that
a cutting tool, over the course of its lifetime, changes from an engineering
item to a logistics item. During engineering, tooling is an area for
process innovation. During the manufacturing cycle, tooling becomes
a productivity driver for the machine tools.
Both of these separate realms can optimize their own flow of information.
However, these areas typically don't view one another as customers.
Engineering has no means to provide value-added service to manufacturing,
and manufacturing has no means to channel its experience and requirements
back to engineering. Providing these means-and therefore the integration-is
the mission of integrated tool management.
Integration Issues
Usually the tool layout is the handover document transferred from
engineering to the shop floor. A tool layout captures the tool information
in the language of engineering, consisting of drawings, bills of material
and parameter lists. A single tool layout refers to a single tool
assembly for a certain operation performed with a specific spindle
on a specific machine tool. The layout documents the components of
the tool assembly, including spare parts. On average, 30 to 50 tool
assemblies are assigned to a machine tool in engine manufacture, with
each assembly including some 230 to 350 components. Tooling engineers
undertake great effort to document all of these components, and yet
the effort is often of little value for downstream activities.
From the tool layout, machine operators and purchasing personnel (or
a full service supplier) pick relevant information for their own downstream
systems. Most of the information needed for these systems is not available
in digital form, so information has to be obtained and keyed in at various
stages. Here are some examples:
- Procurement generates tool packages-that is, bills of
material used to generate purchase orders.
- Shopfloor tool management assigns storage IDs to populate
the inventory management system. Also, tool management adds the distinctions
of perishable versus durable tool components and returnable
versus non-returnable tooling.
- The tool crib physically assembles the tool according
to the tool layout and performs presetting. Correction values are
sent to the NC control.
- The tool crib inspects returned tool assemblies and generates
failure reports.
- On-site cost reduction teams improve cycle times-changing
speed and feed rate or calling for alternate tooling-and thereby change
the tool specification, creating the need for a new release from engineering.
Now consider what effort is involved in these activities. Lost time
can be attributed to these factors:
- Toolsearch and legacy case studies. Including communication
with tool suppliers and machine tool companies, this work alone
can consume up to 50 percent of the tooling group's time.
- Generating tooling packages. This takes approximately
3 days per package, with each package addressing one particular
spindle.
- Populating downstream systems. At a rate of about 2
minutes per item, this translates to about 500 hours for the average
of 15,000 tool items per transmission plant. For an engine plant,
the figure is approximately 200 hours.
Thus the potential savings that integrated tool management can
realize are significant. And these savings do not even include
the savings from higher quality engineering processes. They also
don't include the savings from "deproliferation" programs
that reduce the number of tool items in use.
So why do so few companies practice integrated tool management?
These circumstances, which are typical in large-scale manufacturing
operations, serve as the most frequently cited reasons:
- No commonality in tool descriptions.
- Documentation divided between different systems.
- Graphics and tool data not in digital format.
- No digital information about tool performance.
- No information about which tools are actually in
use.
Compounding these obstacles, collaboration with outside suppliers is
difficult because, in general, there is no electronic supplier integration
beyond electronic data interchange links with major suppliers. Also,
no communication standards are available for collaboration with engineering
partners such as cutting tool and machine tool companies.
These difficulties apply even in the rare situation where the engineering
cycle is supported through effective electronic data management and
the supply cycle is supported through effective shopfloor tool management.
That's because engineering pulls together all relevant information for
a machining process and consolidates this into a single tool assembly,
whereas purchasing must disintegrate the tool assembly to create procurement
packages and populate the downstream systems with data. In addition,
shopfloor management requirements may differ in different locations,
even within the same company.
Case Study
The situation at the powertrain operations of a major automobile
manufacturer reveals the scope of the problem. Here are the key details:
- Five engine and two transmission plants consume an annual
average of $200 million worth of cutting tools, sourced from approximately
150 suppliers (excluding occasional sources).
- Shopfloor tool management is each plant's responsibility,
dealing with 5,000 to 18,000 tool items in each plant.
- Different full-service suppliers are in charge of insourcing,
replenishment and cutter grind at each location, their incomes
depending largely on proven cost savings.
- Process engineering is centralized, but production processes
are supported by local tool engineers.
- Advanced manufacturing is part of the company's tech center.
A preliminary study quantified the tool-management problem. While work
related to documentation accounted for 60 percent of tooling engineers'time,
shopfloor tool managers and full-service suppliers alike testified that
no useful information on tooling was available. Also, 25 percent of
the time on the shop floor was spent on tool searches, mainly to establish
cross references from supplier IDs to the company's IDs. And a random
search at one of the transmission plants showed 28 percent of tool items
are either obsolete (not used for the past 24 months) or redundant (one
of several tool items for the same application). All of other plants
confirmed that this figure was representative for their sites as well.
Management decided to take action at the root of the problem. The company
decided that a system should be put in place that would allow personnel
to reduce the number of tool items in use. The company also decided
that a knowledge base should be established as a communication platform
for future best-practice studies and to promote common engineering standards.
One other requirement was that the system had to reflect the corporate
structure of centralized engineering and purchasing with decentralized
plant operations. No group should be forced to adopt another group's
perspective on the overall process, a requirement that relates most
significantly to the underlying classification structures. If an engine
plant uses an item called "mini-drill," for example, then
another plant might refer to the same product as "micro-drill," and
the system needed to allow for both designations to be correct. From
the start, the company's project team concluded that the push for a
classification scheme that offered only one perspective would lead to
a fatal level of resistance.
The system the company put in place uses Cimsource's corporate software "CS-Enterprise." At
the core of this software is a relational database interfaced to shopfloor
tool management and shopfloor requisitioning. For process engineering,
a direct link to the drawing management system was established. A browser-based
interactive user interface was adapted to each user group's priorities.
Import profiles were designed so they could be tuned to different suppliers'
content, allowing the database to be populated automatically-whether
from the supplier directly, or from Cimsource's "ToolsUnited" master
server, which stores data covering the product ranges of various tool
suppliers.
Two important features led to the successful implementation:
- The complete separation of content from applications.
- The establishment of a master classification scheme that could
serve as a central reference for the different views of the
system seen by different users.
The system was implemented on an existing Oracle database, making it
possible for different views to be cross-referenced, as in the case
of supplier catalogs cross-referenced with internal product codes. In
the application view, cross-referencing allowed engineers and plant
personnel alike to search the database by application. This capability
was pivotal in the attempt to deproliferate the tools in use.
Such deproliferation in the past was compared to a visit to the hairdresser-you
had to do it once in a while. Now it's an ongoing process. A tooling
engineer with a machining problem can specify the problem in a search
through the internal database. If no match is found, the same request
goes out to the ToolsUnited server in search of standard tools to solve
the problem. If there still is no match, only then can a new tool be
created. This is a dramatic departure from the seemingly unbounded creativity
that led to the high level of tool proliferation in the first place.
Deproliferation is also driven by purchasing. Because tools can be
identified by application, the buyer gains engineering intelligence
that was previously unavailable. Redundant tooling becomes obvious.
As a result, purchasing can blind these tools from the database and
wait for someone to complain. When no one complains (the usual case),
the tools can be removed from the database. Indeed, in a typical manufacturing
facility, nearly 10 percent of all listed items can be deleted in this
way within the first 4 months of the system's life.
Best-practice benchmarking also becomes more feasible. A plant manager
can access the database via the plant layouts, identifying a certain
transfer line or flexible cell. From there, the manager can drill down
to the process plan and tool layout, comparing a tool's specification
with any similar line item. Test results from advanced manufacturing
are also published to the system, and in addition, actual speeds and
feed rates can be fed back into the system from the shop floor.
Lessons Learned: The Parametric Master Classification
Integrated tool management focuses on these goals:
- It offers different views of the cutting tool that are
suited to the different perspectives of the various stakeholders
in a tool's life cycle.
- It eases the flow of information through all of the stakeholders'
IT systems.
How these goals are accomplished merits some discussion.
The "different views" objective essentially means that machining
information and tool specifications have to be presented in different "languages." While
the drawing is the language of the engineer, a buyer would rather refer
to a catalog. While the NC programmer is comfortable with a CAD model,
the machine operator wants a printed tool layout. Everyone accesses
the same body of information in different ways. Separating content from
application is the key to meeting this "multi-language" challenge.
Parametrics provide the way to achieve that separation. A cutting tool
is described using all of the parameters necessary to meet the various
management applications along its life cycle. Each application then
accesses only the relevant parameters to populate its predefined models,
templates or tables. This technique is common practice in the management
of standard parts within CAD systems, and any management information
system (MIS) works the same way.
The "easy flow of information" objective is another matter
involving translation. This objective requires that different applications'
exporting and importing activities refer to a common language. Basic
data standards such as ASCII or CSV provide part of the solution, but
meaningful information using one of these standards also has to have
a standard structure. This structure can be predefined between the systems
to be connected, but it can also be part of the transferred data, as
in Extensible Markup Language (XML). The e-procurement "standards" of
ARIBA and CommerceOne take the latter approach, using XML with a predefined
structure to populate their respective procurement platforms.
A classification scheme addresses both structure and parametrics. However,
the problem with this approach is that each company has its own classification
scheme, so mappings from suppliers 'classifications to their customers'classification
are inevitable. What's more, large or multinational companies may maintain
different classification schemes in different locations. The only practical
way to address the discrepancy is with a master classification scheme
able to be mapped to different views.
For the metalcutting industry, a consortium of tool manufacturers and
their customers has worked to define a master classification scheme
that includes requisite parameters for standard tools. The result is
an industry standard for tool descriptions. This standard, called "StandardOpenBase," is
promoted through a joint venture involving Kennametal, Sandvik, Widia,
Plansee Tizit and Cimsource.
StandardOpenBase is now used by a large number of cutting tool companies.
That means there are a large number of suppliers now prepared to quickly
populate a newly implemented system for integrated tool management,
allowing the system to begin delivering its payback that much more quickly.
About the author:
Goetz Marczinski is CEO of Cimsource
Software Company (Ann Arbor, Michigan).
For more information about corporate software from Cimsource, call
(734) 761-8680, enter 37 at www.mmsinfo.com to visit Online Showroom,
or write 37 on the reader service card.
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