TECHNICAL ARTICLE
Originally Printed in the November 2002 Issue of EP&P
Magazine
MAKING SENSE OF CAMX INITIATIVES
A new solution improving information availability is allowing manufacturers
to distinguish themselves as uniquely efficient in the maturing market.
When
a manufacturing industry matures, focus shifts from the race to invent a
process and build production capacity, to the refinement of this
process. This is driven by the natural shift in business drivers. At all
levels of a company, improving efficiency relies on better knowledge of
the performance of manufacturing, either for management purposes or in
the daily effort to improve manufacturing processes. Historically, such
efforts have been hindered by limited access to information from the
process, and inadequate means of exposing this information throughout
the organization. The most fundamental source of factory information is
real-time machine event data.
While technologies from the semiconductor world such as GEM/SECS and a
variety of point-solution software tools built upon this system
attempted to fulfill the need, they failed to gain widespread use and
acceptance in electronics assembly for a variety of economic,
technological, and functional reasons. Fortunately, the emergence of
several software technologies and a data content standard has made a new
solution possible.
BENEFITS OF FACTORY INFORMATION AVAILABILITY
Production machinery used in electronics assembly usually records a
great wealth of real-time process information during operation.
Individual machines maintain their particular form of log containing
each event occurring within its confines. When this information is
harvested and combined with information from other machines and IT
systems, a cross-sectional view of process is revealed. This view can be
at the level of an individual machine, a line, multiple lines, or across
factories.
Information availability serves different purposes in the organizational
hierarchy of the manufacturing enterprise. It empowers managers to
assess efficiency without dependency on time-delayed reports from their
staff, serves as a problem identification and analysis tool at the
quality assurance level, and enables diagnostics, corrective action, and
problem prevention for process engineers and line operators.
Figure 1. Data communications are not limited to the event stream from
machinery. Production programs and commands can be sent into the web
services from the factory’s scheduling or CIM software systems. The
technology can bring the “lights out” factory closer to reality.
The first line of defense against inefficiency is the factory operator.
The personnel operating lines and machines can stop minor problems
before they become serious. Real-time and analyzed trend information
from machines make this early reaction possible. Acting synergistically
with line operators, process engineers are the next to benefit from
information. When engineers refine the process, they need a means of
measuring actual process performance, to understand its behavior.
Understanding the process in actual production conditions enables the
identification of problems, localization of problems to specific
portions of the process, correction, and finally preventive action. The
process engineer's ability to view and analyze the real time information
from the machinery in production lines determines how quickly and
accurately corrections and improvements can be made.
Next consider the quality assurance and production management personnel.
Quality personnel benefit when volumes of information are distilled into
interpretable results. They report on the state of quality, but more
importantly must identify the most significant opportunities for quality
improvement. Production management can better plan and manage when they
have historical analysis of machine performance and workflow.
The most significant impediment to harnessing these benefits has
traditionally been a lack of a reasonable and uniform data transport
technology for production machinery and a data content format standard
to make each information source in the factory appear identical to
upper-level software systems seeking to draw information from them. The
new frontier in data availability solves this problem, and provides
information benefits to all levels of the organization.
PRIOR SOLUTIONS
When most industry professionals consider systems for extracting
information from their machines, they might think of a software "tool"
that harvests data from machines and displays some form of output such
as tables, charts, alarms, etc. Several of these tools are available.
The technology discussed here does not address the "tools" accessed by a
user to view data, but rather the new enabling technology to get the
data from factory assets to the viewing and analyzing software tool. In
order to understand the evolution from past solutions into the new
technology, it is important to first consider the fundamental components
of any system seeking to make factory data available. Any serious
solution requires three key elements.
Figure 2. The XML Web Service model enables machine manufacturers to
easily incorporate the technology to machines and makes the information
emerging from each machine uniformly accessible through the web.
The Data Transport Mechanism: The means of transporting the information
from the machine to a "host" which requires it. Using the analogy of the
digital cell phone, this is the callers cell phone, the transmitters and
receivers, and everything required to convey the digital signal
information from the caller's phone to the other.
Data Content Format: The format of the information is sent from the
machine. Again using the analogy of the phone, this is the standardized
digital format of the voice being transmitted enabling the phones on
both sides of the call to encode and decode the information back and
forth into sound.
Presentation Layer: The technology to present the harvested information
in a manner that has value to an end user. In the cell phone analogy,
this is the receiving cell phone, its software, and amplifier that
reproduces the voice from the digital information sent to the phone.
The prior solutions to make machine information available to the factory
are built on the GEM/SECS communication system, which grew from the
semiconductor industry and was adopted on some machines used in the
electronics assembly industry over the last several years. Software
tools built upon GEM often function only with a limited number or type
of machines, require extensive setup and possibly customization, and are
typically expensive. Unfortunately, GEM has not achieved the market
acceptance or delivered the end-user benefits expected of it in the
electronics assembly industry.
Figure 3. XML web services technology makes information available among
machines as well as to business and process software systems within the
factory.
GEM established strict rules for the data transport, but left the data
content loosely defined and at the discretion of each machine vendor in
critical areas. It did not address presentation at all. For example, GEM
technology requires support for a wide variety of "generic" information
such as "state", which is whether the machine is operating, idle, down
for maintenance, unscheduled downtime, etc. However, for the great
majority of valuable events such as a placement machine's "mispick", or
"feeder depletion", every machine vendor is permitted to define that
event differently. And they did. This is perhaps the most significant
issue that precluded the widespread adoption of GEM in electronics
assembly. Since every vendor defined identical events differently in the
data content their machines sent out into the world, the presentation
layer, or software tools which analyzed the data, could not uniformly
interpret this information without customized interfaces for every
machine vendor and machine type. From the perspective of software
systems designed to present machine data to a user, monitoring a factory
containing different brands of SMT machines using GEM is like listening
to a choir with each member singing the same song in unison, but each in
a different language. The content of the song is all present, but very
difficult to sort out.
Cost and difficulty of implementation also conspired against the success
of GEM in electronics assembly. It is built upon rather dated software
technology, and the development toolkits to utilize it are expensive for
both machine vendors to incorporate on their equipment, and for third
party software suppliers to incorporate into their presentation tools.
The difficulty and cost of implementing was then passed onto the
customer through high-cost tools to utilize the technology. Far more
modern software technologies are possible today to meet and exceed the
capability of GEM communications, with significantly less cost and
implementation burden.
In summary, a new technology was required to bring information
availability to the electronics assembly factory.
UNDERSTANDING THE NEW SOLUTIONS TECHNOLOGY
A technology that could be easily incorporated into any machine or other
information-generating entity was needed to "expose" standardized
information using standardized web technology to the outside world. The
emergence of web service software technology along with the IPC 2540 (CAMX)
data content specification, has enabled the creation of a platform
making information from a variety of data sources in the factory easily
and uniformly available.
The technology uses the XML web services architecture as a data
transport mechanism. The data content communicated to and from the
machinery is in XML format, following the IPC CAMX standard. The
application of this technology turns each machine or other data source
within the factory into a web-serving "black box" offering a consistent
method of presenting information and accepting information from the
outside world.
This combination of software architecture and a reasonable, uniform data
format meets the following key requirements:
Accessibility: Whereas prior technologies required significant
developmental efforts to cope with proprietary communications and
formats, everything about the new technology is universal. The data
content is XML, which is supported by many software development
toolsets, expediting development.
Standardization and Cross-Vendor Uniformity: Each machine or other data
source defines the same event in the same way within the data format.
Third-party presentation tools can access one machine in the same manner
as any other, without customization or special connections.
Simplified Integration: Machine vendors have access to a greatly
simplified tool to expose their machine's data to the world, and give
their machine's information a "web portal". The web service incorporated
into each machine takes care of all network, caching, information
serving across the web, and other burdens for the machine vendor.
The XML web service used in this technology overcame the technical
roadblocks; certain issues were regarded as inherent to a disconnected,
web-architecture, real-time monitoring system. For example, the need for
reliable sequential timing of incoming events was thought to be a
problem in a system that does not maintain continuous connection to all
of its data sources, and therefore won't necessarily receive events in
perfect sequence. This was overcome through use of industry-standard
time server and synchronization technology and an elegant "handshaking"
technique each web service employs.
APPLICATIONS WITHIN THE FACTORY
Information is valuable to process engineers in their pursuit of
refinements, to business systems for the functions of inventory and
scheduling, to CIM systems for quality and performance tracking, and
even to other machinery in the line, which could adaptively react to
real time conditions downstream if only they had access to the
information. Information availability in the factory using the XML web
services model opens more opportunities to leverage information than can
be gained only from accessing machinery in the lines from a host
application, as the model functions point-to-point as well as from
point-to-host. Consider the following capabilities inherent to the XML
web service which extend far beyond the capabilities of previous factory
data communication techniques.
Information Extraction
Each machine presents its own web portal.
Runtime events from assembly and process machines.
Inspection results from test, AOI, AXI, etc.
Real-time data from environmental monitors.
Real-time data from custom systems, functional testers.
Events and data from third-party business systems such as ERP.
Reciprocal communication with factory CIM systems.
Information Feedback
Program download from CIM systems.
Machine-to-machine feedback channel such as from AOI to pick-and-place.
Control Interface
Remote control capability.
REALITY NOT A CONCEPT
Fortunately, this technology is not merely a proof-of-concept exercise.
It is a working commercial product presently being integrated by
tier-one machine manufacturers as a component of their machine software.
The types of machines include placement, AOI, and various process
machines such as printers, ovens, and dispensers. The integration allows
not only third-party software systems to communicate with the machines,
but any web browser can access the web server on the machines to view
their event information instantly. In Q1 2003, a standard developer's
document will be made available free of charge on the web at
www.aiscorp.com defining the methods of accessing the web service on
these machines. This will allow any third-party programmer to easily
connect to and benefit from the machine information using mainstream
software development tools, not proprietary methods or toolkits. The XML
web service may also be attached to any other machine or system via its
"adapter" architecture, which allows developers to easily connect it to
any system, including non-Windows platforms and systems.
CONCLUSION
Soon electronics assembly factories will no longer be filled with
machines hiding their valuable performance and the process information.
Managers will not wait days or weeks for performance and quality data,
but will access it in real time. Process engineers will not rely on
tribal knowledge of performance history, and instead will have the
information they need to push process refinement to new levels. The new
frontier brings factories of web-serving machines, communicating with
one another and with the organization. These factories succeed in the
new marketplace because their physical assets and personnel use
information in a concerted effort to continuously improve efficiency.
Author Information:
Jason Spera, Chief Executive Officer
Aegis Industrial Software Corporation
220 Gibraltar Road, Suite 100
Horsham, PA 19044