QMT Features: June 2009
Integrated Manufacturing
Integrated Manufacturing can deliver true Six Sigma through the integration of data and process control in real time, using the internet to track quality and automatically adjust manufacturing processes.  By Kevin McGushion


Manufacturing has had the benefit of computerized control systems and rapid exchange of data for many years.  This has lead to advanced robotic assembly as well as automated production lines.  However, there has never been a broad integration of data and process control in real-time in order to have an immediate impact on the process of joining components. 

A vast amount of information already acquired by component manufacturers is relegated to archive status and is almost never pulled into the manufacturing process.  This valuable data has the potential of not only improving the process but reducing labour and cycle time, as well as creating hyper awareness in manufacturing.

A large portion of quality cost is in the documentation created during quality inspections.  This documentation may be electronic or paper based and is almost always collected by the manufacturer and is almost never made available to the user even though he directly benefits from this quality data in the form of a more reliable product and he certainly pays for that quality in the purchase price. Except in rare instances where the user specifically needs or requests this data such as in high tech industries, this data is usually stored or discarded and is inaccessible by the user; but, even where the data is provided it is usually in paper form which is inherently cumbersome in modern manufacturing environments.  Often this data, merely given a cursory glance, is rarely leveraged into the next manufacturing step and fails to build on existing quality and/or be linked to the next manufacturing steps.

 At a time when 6 sigma quality drives much of the expectation in manufacturing, where only 3.4 defects in 1 million are allowed, the tools to realize such a goal are woefully inadequate and do not take into account the dynamic nature of the component or process joining them.  Indeed, manufacturing quality has relied on a static model which held the process and components close to a band of variables as determined by a specification.  However, manufacturing specifications that define the band to which most commercial products and components are held usually consider the needs of the final product and not the processes that join its components. 

The specification of a component can allow as much as a 20% variation in characteristics, while the process intended to join that component to another rarely has the ability to account for such a large deviation in real time.  A case in point is the ASTM specification A632 which states that the wall thickness of a tube can vary by +/- 10%, for an overall variation of 20%.  If a tube has a wall thickness of .049” the actual thickness that could be encountered is from .044” to.054”, this constitutes a very large change, especially since it is generally understood by welders that for every mil of wall thickness change a weld schedule must change about 1 amp.  Similar variations are allowed in fasteners, such as bolts, where large variations in diameter and coefficient of friction have a meaningful and direct impact on the quality and cannot currently be adjusted for in the joinder process.

The component manufacturer will often produce a certification of the exact qualities of a component, including dimensional and chemical composition, to prove that it falls within the specification window.  At a minimum, a manufacturer will subject components to a statistical process control and will have acquired specific data relating to a batch of parts.  This specific information almost never makes it to the process controller and almost never has an opportunity to affect the process that will join it.  This data normally takes a separate path, gets compiled with other related data and gets stored or presented to a customer who in turn warehouses it.
This now “dead data” beyond providing compliance information to a specification, had no effect on the joining processes and will have no future effect on how the product is used, maintained or recycled.

What is needed
What is needed is a system that compiles the data already being collected by a component manufacturer and holds that data in an easily accessible storage location.  The component related to that data must be identified with an indelible means of machine readable code that is permanently linked to that data location via the internet.  That data must be organized in a hierarchical manner which gives preference to information that most influences the process being used to join one component to another. 

The data produced during a joinder or welding process must be linked to the data associated with the components it has connected, creating a complete quality picture of an assembly.  This complete data must be stored so that it may be accessed during the life of the product for maintenance and performance evaluation.  This data must also be accessible during the recycle phase of a product to ensure that “best recycle practices” are used to reclaim useful materials.  This data must also be accessible by MRP, ERP, financial and management software to create a whole, hyper aware and hyper traceable manufacturing system. 
In creating such a system traditional mass production technologies can be upgraded to utilize mass customization of the process.  Heretofore, such a goal has been impossible but completely necessary in order to meet the modern goals of production, quality, tracking and environmental safety.

Integrated manufacturing in orbital welding
While IM can be applied to almost any industrial joinder process, orbital welding represents an excellent starting point because of the relative ease with which the data can be accessed and stored.  The components that are used for orbital welding especially in the semiconductor, biopharmaceutical, aerospace and nuclear industries are already subject to certification that lends itself to electronic data management and quick identification.  The certification information of components can be stored so that when an orbital welder is preparing to make a weld between two components the computer power supply can access this critical data and pull it into the joining process.  By pulling in this process critical data or PCD, information that has an immediate and direct impact on the success of that weld can be presented to the computer power supply in real time.  Because this data is presented in real time, software on board the power supply can adjust the weld parameters before the weld is made, greatly improving the likelihood of a successful weld. 

Pulling in PCD also reduces the time required to evaluate a component and make necessary adjustments, assuming this step happened at all.  In most cases slight variations in material or geometry, that still meet the requirements of a specification are only discovered after and unacceptable weld has been made. This accounts for substantial rework time, setting back work schedules as well as loss of components and profit.

After leveraging PCD to yield an optimum weld result, the quality data collected by the power supply during the welding process can be used to complete the quality picture of an assembly.  Using the weld quality data to create a link at joinder between two or more components allows the binding of data from one component to another ad infinitum, irrespective of the size of an assembly.  By retrieving the data of one component, the data for all the components and their joinder information for an assembly are also retrieved.  This adds value in determining the exact content of a manufactured product and the real time part usage and labour content of a manufacturing process.

 Customers often require all documentation relating to the components and the welds in an assembly to be submitted to them in what is called a turn over package or TOP.  This documentation requires many hours to complete and like the certification of a single component will have no meaningful impact of how the product will be used, serviced or recycled.  This TOP is stored and becomes dead data and beyond verifying compliance to a customer specification it served no other useful purpose.  With IM a virtual TOP is created as a matter of course and can be accessed by a customer for large savings in time and money with the added benefit of greater reliability.

Implementation in orbital welding
The first step in implementing IM is the creation of a web enabled part number or WEPN.  A WEPN automatically launches an internet search for data when it is scanned, pulling in the information and PCD associated with a specific component.
The WEPN  is a unique code that contains three important components:

  • A Primer
  • A Correlation Site
  • An Encoded Path

The Primer is a character or series of characters somewhere in the WEPN that tells the IM software that this is a WEPN.  For this application the ‘@’ symbol is used and it is placed at the beginning of the WEPN.

The Correlation Site is a site where a correlation or look-up table for the Encoded Path exists.  The correlation site has security features allowing restricted access to data in a WEPN.  The Correlation Site consists of ASCII characters giving over 9000 different security protocols for a WEPN.

 The Encoded Path consists of a unique series of ASCII characters and makes up the remaining 12 characters of the WEPN.  When the encoded path is matched to an address or location at the correlation site, the data for that WEPN is made available to the user according to the level of access granted by the security protocol.  The purpose of the encoded path is to abbreviate the address location of data, especially when that data is accessible through the internet where extremely long URL addresses are common.

The figure above shows what an actual WEPN looks like in machine readable Code 128 Barcode.  Because the code is ASCII based and there are 95 possible printed characters in each location there are an extremely large number of permutations possible.  Given the encoded path is 12 characters long there are as many as 5.4 x 1023 or .54 septillion possible addresses for data to be found.  This would provide unique data locations for more parts than have ever been manufactured by industry.  This is the equivalent of giving every person on the planet 15 million 747’s worth of parts, given there are 6 million parts in a 747.  This allows unique identification of every nut, bolt, washer and component in manufacturing.  The barcode in Figure 3 has all the necessary components of a WEPN, the ‘@’ primer, the ‘aL’ correlation site and the encoded path of ‘o4@/w*^M?n2)’.   This barcode is about that same length as a common UPC barcode on an item in the grocery store.  WEPNs are not limited to barcodes and can include any machine readable technology.  Now that we have a WEPN we must link it to a specific part. 
When a component is made great pains are taken by the manufacturer to ensure that it meets the specifications that the customer and or a controlling body determine is necessary.  In doing this, large amounts of data are produced regarding a parts dimension, material composition and assembly.  Certain information may be requested by a customer to certify that the part complies with a specification however; other information not requested may be archived by the manufacturer or simply discarded.  This information can be extremely valuable in determining the exact settings of the joinder process used to connect it to another part and must be saved for that use creating a repository for this information.  In orbital welding such PCD may be wall thickness, diameter and sulfur and manganese content along with any special instructions to be followed during welding or assembly. 

The PCD of a component must be stored in a location identified by its WEPN so that it can be retrieved instantly by simply scanning the WEPN.  The data is organized in a manner that best suits the process that is to be used.  For instance, if orbital welding is to be performed, wall thickness, tube diameter, sulfur and manganese content is prioritized as process critical and is fast tracked to the process controller.  Whereas, if a face seal fitting were to be tightened, coefficient of friction and thread diameter would be process critical.

Once the PCD is pulled into the process, small changes can be made to the welding parameters automatically customizing it for that particular joint.  Slight variations in material composition and dimensional compliance which were previously unknown to the process operator and yet had significant affect on the weld are now considered.  Of great importance is the fact that the entire process of modification can be behind-the scenes with the operator either unaware of the changes or given summary information of the modification.  To achieve this, the only additional task performed by the operator would be to scan the WEPN’s.  It is conceivable that in 1000 welds there could be 1000 different weld parameters creating true mass customization of process.  However, each weld is optimized automatically to yield the same final result.  It is better to have 1000 different schedules instead of 1000 different outcomes.

During the welding process, control variables such as current, voltage, purge pressure, flow and even the purity of the purge gas are monitored and stored as a weld report.  This weld report receives the same treatment as the certification report of a component and likewise can yield valuable information to subsequent processes and to the larger assembly.  For this reason this information is incorporated in the total quality picture of the assembly and the quality data from the joinder process becomes the link that attaches the data of adjacent components. 

This connection is called link at joinder and creates a virtual link between the data of components that mirrors the physical link of the parts in an assembly.  As previously described this linking can continue for any size assembly creating a continuous chain of quality and data for every component in a machine.  Because of this linking, any component can be scanned in an assembly and the data for every component and joinder process in that assembly becomes instantly available. 
If for instance IM were used to assemble a 747, the WEPN of a lug nut on a wheel of the plane could be scanned and the information on the rivets of the right wing could not only be immediately recalled but information on the technician who installed it and with what tool and to what values could also be viewed. 
Likewise maintenance data is collected.  When a part is serviced, its WEPN is scanned and the service report is uploaded.  If a part is replaced, the WEPN of the old part is scanned out and the new part scanned in.  This creates a permanent web based service log for any assembly. 

Finally, when a product that was made and maintained with IM is retired for recycling the best methods for recycling can be determined based on the exact content of that product.

Email: kevinm@intmanufacturing.com
www.intmanufacturing.com

  
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