Koren Y. The Global Manufacturing Revolution: Product-Process-Business Integration and Reconfigurable Systems
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On some high-production lines, single dimensions are sometimes measured in-
process by using dedicated gauges. Each gauge can measure only one dimension, and
has to be replaced when the part is changed. These gauges are useful only when the
line produces only a single type of parts, and the measured dimension is at a known
location on the part.
The RIM: It is composed of a precision conveyor moving the part along
one accurate axis of motion within an arr ay of electro- optical devices such as
digital or line scanning cameras, and lase r-based sens ors. The locat ion of each
sensor can be changed to fit the geometry of the inspected part. Columns of non-
contact electro-optical sensors may be located on both sides of the part, as
shown in Figure 8.14, and an additional array of sensors can b e positioned above
the part. These linear scans can determine surface profile, flatness, parallelism and
distance between machined surfaces, distance between machined holes, and other
features.
Another approach using the RIM is to move the sensors past the stationary part. In
either case the time required to complete the measurement should be synchronized
with the normal cycle time of the manufacturing line—typically 20–30 seconds on
engine production lines.
In order to adapt the machine for the measurement of a different part of the same
part family, the location of the sensors around the m achine is reconfigurable. To
utilize the RIM reconfigurability, the geometry of the parts on the production line
Figure 8.14 A schematic of a reconfigurable inspection machine (RIM).
RECONFIGURABLE INSPECTION MACHINES 221
is known at the outset. Table 8.4 compares the conventional measuring methods
with the RIM.
A RIM for measuring surfaces on cylinder heads is shown in Figure 8.15. In this
photo two laser-based sensors are shown on one side of the part; three additional laser
sensors are located on the other side of the inspected part, as well as an accurate
computer-vision system.
RIMs are also useful for detecting and analyzing porosity flaws in machined
surfaces. Surface porosity, in the form of tiny voids or pits in the surface of machined
castings, can severely degrade the quality of precision-machined components such as
engine blocks and cylinder heads. Such voids occur in the casting process when gases
are trapped as the casting solidifies. If the void is exposed during machining, it leaves
a small pit in the surface.
Depending on where they occur, surface pores can create significant leaks of
coolant, oil, or combustion gasses, even though they may be less than 1 mm in
diameter. If these pores are not detected, they can cause severe damage to engines and
transmissions, and at the very least, consumer could end up with a noisy engine with
a shorter usable life. If they are detected in later stages of machining, the unit will be
Figure 8.15 A photo of the RIM with its optical sensors.
TABLE 8.4 Inspection Machines
Dedicated Reconfigurable Flexible
Contact gauges RIM CMM
Very fast Fast Very slow
Not flexible Customized flexibility
for a part family
Full flexibility
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scrapped; wasting all of the machining that had been performed up to that point.
A RIM equipped with a camera and computer vision software can successfully detect
pores at the line speed of 20 seconds.
The following article, taken from the NSF ERC Showcase website
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shows an
implementation of our RIM technology at GM Flint Engine Plant.
The integration of RIM systems into production lines enhances productivity and
improves the accuracy of production for the manufacturer, and the quality of products
going to the consumer.
RECONFIGURABLE INSPECTION MACHINES 223
BelowaretwoprofessionalevaluationoftheRIMprovidedbyourformer
students.
“RIM brings real-time automated inspection to the plant floor. In addition to raising quality
at line rate this can also decrease the time required to reach production level targets during
ramp-up. This is extremely valuable to the personalized production paradigm because
companies can react more effectively to changing markets.” David Matthews
“The use of a CMM is slow and the feedback loop, if something is out of specification or
control, is long. In an automotive body shop, the sheet metal parts are critical to the overall
exterior fit of a vehicle. But there are only a few parts measured, and that is by shuffling parts
back and forth to the CMM room. By the time anyone realizes that anything is out of control,
many parts have been made. A RIM could be placed on line, integrated into the manufactur-
ing system, and then part changes could be detected quickly.” Cindie Niemann
8.6 OPEN-ARCHITECTURE CONTROLLERS
Designing modular and RMs creates a need for corresponding RM controllers to
facilitate that flexibility. Such controllers are based on open-architecture principles.
Open architecture allows the adding and swapping of control modules to fit changing,
specific applications. IEEE standards define an open system as
An open system providing capabilities that enable properly implemented applications
to run on a wi de variety o f platforms from multiple vendors, inter-operating with
other system applications, and presenting a consistent style of interaction with the
user.
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Global researc h efforts have been dedi cated to developing open architecture
control systems. The three mos t important initiatives have been: the EU project,
OSACA, and its German successor, HU
¨
MNOS; the Japanese initiative OSEC; and the
North American OMAC-TEAM project
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. The OSACA project focused on reference
architecture for control systems. The main outcome from OSACA is an object-
oriented design as well as specification of a vendor-neutral open architecture for
machine control systems. OMAC was an initiative driven by General Motors, Boeing,
and NIST to establish a set of Application Programming Interfaces (APIs) to be used
by vendors to sell reconfigurable, customized cont roller products to the aerospace and
automotive industries.
Open-architecture systems may include a library of control algorithms (e.g.,
servos, temperature control, interpolators, etc.) that can be easily integrated into the
machine software when needed for a new application.
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The desired control modules
are selected and integrated using a “Control Configurator” for the selected machine
and application. The Configurator also checks its real-time constraints. After the
experimental execution of the configuration process, control code is generated. This
can be carried out according to either vendor-neutral or vendor-specific formats, and
converted into PLC or NC code.
224 RECONFIGURABLE MACHINES
TABLE 8.5 Characteristics of an Open Control System
Modularity Decentralized structures are supported by distributed application modules
Integrability Integration of hardware and software components that communicate with
each other
Scalability Increased performance by processor upgrade and added application
modules
Convertibility New functionality by adding hardware modules and software application
modules
Customization The ability to exchange control modules to meet new specific
applications
Diagnosability The ability to easily diagnose control software problems after
configuration
The system software for an open control system has to contain:
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1. An operating system to execute the software module functions.
2. A communication system to enable information interchange between modules
utilizing a standard protocol.
The controller’s openness is the enabling tec hnology needed to integrate, extend,
replace, and reuse hardware and software components in a control system. The open-
controller should possess a set of core characteristics (Table 8.5) similar to those for
RMs.
The functionality of the system software is derived from the application modules.
Integrability leads to the definition of a uniform API that allows modu les to be
interfaced into any system platform that supports them, as well as changing config-
urations by repositioning modules in the system. It implicitly demands that system
software shield the application from the system hardware. Although on a physical
level combined control components depend on the control system platfo rm, the
platform itself looks transparent to the user, since a set of uniform APIs is provided for
the application software. The API hides all hardware details and offers one homo-
geneous platform even in distributed control systems.
A specific system platform with these characteristic s was designed and imple-
mented by the Europe an OSACA initiative.
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This software can very easily be ported
to different operating systems and it suppor ts real-time features. A wide range of
communication networks (such as Sercos, Profibus, Ethernet) is available for the
physical coupling of distributed platforms.
Finally, it is important for software modules to correspond to the hardware
components of the machine. This means that, using object-based principles, a
machine object corresponds to a controller object that runs the control functionality
of the machine object.
PROBLEMS
8.1 Which of the six core characteristics are contained in the RMTs depicted in
Figures 8.7, 8.9, and 8.12?
PROBLEMS 225
8.2 What are the RM design principles that the RIM in Figure 8.14 obeys?
Explai n.
REFERENCES
1. Y.Koren,F.Jovane,U.Heisel,T.Moriwaki,G.Pritschow,G.Ulsoy,andH.VanBrussel.
Reconfigurable manufacturing systems. CIRP Annals, November 1999, Vol. 48, No. 2,
pp. 6–12.
2. R. Landers, B. K. Min, and Y. Koren. Reconfigurable machine tools. CIRP Annals, July
2001, Vol. 49, No. 1.
3. Y. Koren and S. Kota. Reconfigurable machine tool. US patent #5,943,750, August 31,
1999.
4. Y. Koren and R. Katz. Reconfigurable apparatus for inspection during a manufacturing
process and related method. US patent #6,567,162, Issued on May 20, 2003.
5. IMS Report. Joint International Research Programs into an Intelligent Manufacturing
System, International Robotics and Factory Automation Centre (IROFA), 1990.
6. G. Rogers and L. Bottaci. Modular production systems: a new manufacturing paradigm.
Journal of Intelligent Manufacturing, 1997, Vol. 8, pp. 147–156.
7. Y. Koren, Y. Moon, and S. Kota.Reconfigurable multi-spindles apparatus. US patent
#6,569,071, Issued on May 27, 2003.
8. Y. Koren and S. Kota.Reconfigurable machine tool. US patent # 5,943,750, August 31, 1999.
9. E. Shamoto and T. Moriwaki. Rigid XY Table for ultraprecision machine tool driven by
means of waling drive, Annals of the CIRP, 1997, Vol. 46/1, pp. 301–304.
10. K. Youcef-Toumi and J. H. Buitrago. Design of robot-operated adaptable fixtures. ASME
Symposium on Manufacturing System, Atlanta, Georgia, 1988, pp. 113–119.
11. D. Chakraborty, E. C. De Meter, and P. Szuba. Part location algorithms for an intelligent
fixturing system—parts 1 and 2. Journal of Manufacturing Systems, 2001, Vol. 20, No. 2,
pp. 124–134 and 135–148.
12. C. H. Shen Y.T. Lin, J. S. Agapiou, G. L. Jones, M. A. Kramarczyk, and P. Bandyopadhyay.
An innovative reconfigurable and totally automated fixture system for agile machining
applications. Transactions 31st NAMRC, McMaster University, Hamilton, Ontario,
Canada, May 2003.
13. http://showcase.erc-assoc.org/accomplishments/manufacture/rms-07-1-porosity.htm
14. G. Pritschow, Y. Altintas, F. Jovane, Y. Koren, H. VanBrussel, and M. Weck. Open-
controller architecture—past, present, and future. A keynote paper. CIRP Annals,
November 2001, Vol. 50, No. 2, pp. 463–470.
15. Y. Koren, F. Jovane, and G. Pritschow (eds). Open Architecture Control Systems, Summary
of Global Activity, ITIA Series, Vol. 2. Milano, Italy, 1998.
16. Y. Koren, Z. Pasek, G. Ulsoy, and U. Benchetrit. Real-time open-control architectures and
system performance. CIRP Annals, July 1996, Vol. 45, No. 1, pp. 377–380.
17. G. Pritschow et.al. Modular system platform for open control systems. Production
Engineering, 1997, Vol. 4, No. 2.
18. W. Sperling et al. OSACA ESPRIT 6379/9115 Final Report. FISW GmbH, Stuttgart,
Germany, 1996.
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Chapter 9
Reconfigurable
Manufacturing Systems
Manufacturing companies in the twenty-first century face increasingly frequent and
unpredictable market changes driven by global competition, including the rapid
introduction of new products, and constantly varying product demand. To stay
competitive, companies must design manufacturing systems that not only produce
high-quality goods at low cost, but also allow for rapid response to market changes and
consumer needs. Reconfigurability is a novel engineering technology that enables
cost-effective, rapid responsiveness to market and product changes. A reconfigurable
manufacturing system (RMS), including reconfigurable machines and open con-
trollers, is the corne rstone of this new paradigm.
9.1 THE CHALLENGES OF GLOBALIZATION
To compete globally, the manufacturing plant should stand on three legs: cost, quality,
and responsiveness (Figure 9.1). This means that manufacturing plants have three
goals: produce at low cost, enhance product quality, and respond to change rapidly and
effectively. Responsiveness means the speed at which the plant can fulfill changing
business goals and produce new product models.
9.1.1 Cost
No business can compete for long if their products cost more to produce than those of
their competitors. Producing at the lowest possible cost and continuing to innovate
The Global Manufacturing Revolution: Product-Process-Business Integration and Reconfigurable Systems
By Yoram Koren
Copyright 2010 John Wiley & Sons, Inc.
227
and introduce new products in the competitive global marketplace is an on-going
challenge for all manufacturers. Cost and profitability depend on many different
factors. Equipment purchases, floor space, operational requi rements, and tooling
costs are only part of what is entailed in bringing a product online. Another concern for
competitive manufacturers is the cost of NOT bringing a product to market. Failing to
capitalize on a market opportunity by getting a potential blockbuster product out too
late is another way that manufacturers can lose.
As we will show, manufacturing systems that use reconfigurable components and
architectures can offer a much greater range of options to man ufacturers. Adjustable
capacity and flexibility, along with new tools for designing systems and getting
production up and running, are a hallmark of reconfiguration design. Timely
reconfiguration reduc es the time-to-market and provides precisely the quantities
needed at the lowest possible cost.
9.1.2 Quality
Making sure that your products are made to the highest quality possible is critical to a
manufacturer’s success. In manufacturing, there are two areas where product quality
can make the difference between success and failure: the quality that your customer
sees when they buy the product, and the qual ity that they will see over time.
The quality your customer sees depends for the most part on the quality of the final
assembly. This quality should even exceed customer’s expectations. Being aware of
Figure 9.1 Goals of manufacturing plants.
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RECONFIGURABLE MANUFACTURING SYSTEMS
the expectations of your customers has always been good advice, but in the era of
globalization delivering a product that its quality exceeds expectations is a strategic
necessity. Remember, everyone wants to think they got more than their money’s
worth.
On the other hand, the quality that the cust omer sees after long use of their product
is the feature that keeps customers coming back and builds a brand. Improving
the product design through reliability testing, stress analysis, etc. can produce a
superior product on paper, but manufacturing is a key to get a consistent quality in
every product. Manufacturers must develop produc tion systems that are able to
consistently produce every product and part without variation. And when variation
occurs, as it inevitably does, it must be corrected at the earliest possible moment to
keep from wasting valuable time, energy, and material.
Detecting flaws and removing them from the output product is critical to success
but current methods of detecting variation on the production line are frequently too
slow to be effective. Quicker, cheaper, more systematized solutions must be im-
plemented. In-line inspection tools improve operational consistency so long as they
do their jobs quickly and can be applied to every part produced, instead of merely
occasional sampling. That way they can detect and localize errors before large
quantities of flawed parts are created and production is wasted. These inspection
tools also need to be readily and efficiently reconfigurable to be useful for whole
part/product families.
9.1.3 Responsiveness
Responsiveness enables manufacturing systems to quickly launch new products on
existing manufacturing systems, and to react rapidly and cost-effectively to:
1. Market changes, including changes in product demand (even after production
started).
2. Product changes, including changes in current products, and new product
introduction.
3. Government regulations (safety and environment).
4. System failures (keep production up despite equipment failur es).
All these changes are driven by aggressive competition on a global scale, more
educated and demanding customers, and a rapid pace of change in product and process
technology.
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Remember: The Speed of Responsiveness is the New Frontier of Manufacturing
Enterprises. Although responsiveness is not yet attributed the same level of
importance as cost and quality, its impact is quickly becoming an equal imperative.
Responsiveness provides a key competitive advantage in a turbulent global economy
in which companies must be able to react to changes rapidly and cost-effectively. This
can often be done by installing a manufacturing system with modest initial capacity
THE CHALLENGES OF GLOBALIZATION 229
that is designed for adding production capacity as the market grows, and adding
functionality as the product changes.
When analyzing profitability, the value of operational responsiveness should be
considered. Responsiveness includes the ability to adjust production volumes
efficiently and rapidly change production mix among product variants and models.
Today, new products have very short windows of opportunity to penetrate into the
market. The speed at which a manufacturing system is ready to produce a new product
at the required quantity and quality is critical to success. Computer-aided design
(CAD) has dramatically reduced product development times in the last three decades
(Figure 9.2, top); such design innovations are needed for the manufacturing system
itself.
The lead time to design and build or reconfigure a manufacturing system, and the
time needed to ramp it up should not become a bottleneck to full-volume, high-quality
production. If manufacturing system lead time can be reduc ed, brief windows of
opportunity for new products can be captured economically and result in major
economic savings. Figure 9.2 (bottom) depicts how rapid reconfiguration of existing
manufacturing systems reduces lead time and brings more products to market faster.
In order to produce new products and accommodate changes in existing products,
new functions must be added to the manufacturing system through reconfiguration.
A well-designed RMS can be converted to consistently accommodate the production
of new products for many years allowing for several reconfiguration periods over its
lifetime, as depicted in Figure 9.2. To be successful, short ramp-up periods are needed
after each reconfiguration to bring the system back on line quickly. This type of
reconfiguration requires rapid system convertibility to add new functions.
Figure 9.2 Product development time was reduced dramatically by the introduction of
CAD systems. However, something equivalent has yet to be done with the manufacturing
system (top) itself. Increasing the frequency of new product introductions requires
shortening the manufacturing system lead time, enabled through rapid reconfiguration.
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