Plexus Online - Bytec Case Study

Plexus Online Traceability System Key
In Sourcing Decision

Bytec, Inc. Lands Contract with Tier One Supplier

In the fall of 2004 a major Tier One automotive company was searching desperately for a new supplier for the unitized center bearing (UCB) used in its customers' cars and trucks. It was resourcing the UCB because the previous supplier had serious quality problems, which exposed shortcomings in its inventory control and increased the potential of future warranty costs to the OEM.

Bytec, Inc, located in Clinton, Michigan, pitched the business. It knew it had the experience and ability to make the part, but the Tier One demanded more than production capability. It wanted proof of a strong traceability system before awarding the work.

Bytec turned to Plexus Systems to help it establish the robust process and inventory control it needed to win the business. Plexus Systems provided Bytec with the Plexus Online Manufacturing Execution System, which was used by Bytec to manage part serialization, bar coding, component tracking, quality management, SPC/measurement data, and full part traceability. For each piece in the field, Plexus Online now provides the production date/time, the machines and operators that made it, the in-process measurement data, the supplier and serial numbers of the components that went into it, the steel chemistry of the raw material, and much more. All the data is there, easily accessible in real time.

The UCB is a combination bearing/vibration damping device that bolts to the frame of rear-wheel-drive vehicles, limiting driveshaft bowing and vibration. It's critical for reducing noise, vibration and harshness (NVH) and, ultimately, cutting warranty costs. Bytec management knew they could not afford to take on this difficult business without a strong system to protect them, something that would give them the tools they needed to identify and correct material and manufacturing issues that they had inherited with an existing design.

Reducing warranty costs is crucial to the Tier One supplier and the automotive industry. The U.S. spent more than $25 billion on warranty costs last year, 50% of this came from the US automotive industry. At least one automaker has said it will charge the supplier for half of the total recall cost and will deduct the money from the supplier without negotiation. Do the math on those warranty costs and it's no wonder the Tier One was all ears when Bytec promised every part it shipped would have a unique identity with full traceability back through the entire process. Quickly limiting the scope of any problem is key to minimizing the potential damage and cost.

Success or Failure - Traceability was the Key

The Tier One's previous UCB supplier could not provide the necessary process and inventory controls to address the part's inherent challenges and almost went out of business trying. Its quality problems began when a rubber bushing sometimes became too hard, which reduced the UCB's dampening ability and allowed normal driveshaft vibrations to be transmitted into the passenger compartment. Since each part was labeled with only a Julian date, all parts marked with that date were suspect. Even if all the UCBs from that day were contained, there was no traceability to ensure the Tier One's parts produced the days before and after shouldn't be contained as well. This resulted in large and expensive containment campaigns whenever a problem occurred. Even more importantly, there was nothing to help the supplier understand, contain and correct the root cause of the problem. The supplier chased the problems for months, spent millions of dollars, and eventually cried uncle.

Using Plexus Online, Bytec now certifies the quality of each UCB, provides traceability back to each subcomponent and manufacturing step and delivers the statistical capability of each container of parts. If any problems occur, they can be tracked down, understood and permanently corrected in a systematic way. In less than a year, the quality performance (as measured in parts-per-million defective) has been reduced from over a thousand in 2004 with the previous supplier, to six PPM in 2005 with Bytec using Plexus.

A part that was a costly struggle for one company has become profitable for another.

The Glyph - Direct Part Marking

The initial approach to the Bytec project involved laser-etching an encrypted serial number of each part directly onto the steel surface. However, the laser-etching did not survive the 96-hour salt spray test and the other reliability checks. Plexus eventually solved the problem using a specialized Mylar label from 3M with advanced adhesive properties that sticks to metal. The label approach turned out to be far less expensive (requires a label printer instead of laser equipment). Most importantly, the specialized label passed all reliability tests with flying colors (or in this case, black and white).

Each part is identified with a unique serial number. The serial number is encoded into a specialized symbol called a glyph, a symbology from InfoGlyph USA, Inc. Similar to the standard data matrix symbology, this square two-dimensional bar code contains the information Plexus needs to identify and track the part. One of the advantages of the glyph symbol is that up to 80% of the mark can be destroyed and it can still be decoded.

The glyph is encrypted, which offers counterfeit protection, another growing problem in the automotive industry. The encrypted serial number allows Bytec and the Tier One to verify that it is a genuine part and not a knock-off from China. This ability further helps with warranty costs. OEMs are finding it increasingly unpalatable to pay warranty, quality and safety costs on the failure of components that they didn't even make. The Plexus Online solution solves that problem.

Control Plans That Actually Control

Inventory control is essential, but quality starts with engineering and quality planning and continues with the implementation of process control on the shop floor. The Plexus Online system controls the engineering specifications (dimensions & tolerances), the routing, the approved machines, the FMEA and Control Plan, the setup and operation instructions and all other aspects of the manufacturing process.

In the past, in a typical manufacturing company, the Control Plan was a piece of paper or an excel spreadsheet that the quality manager updated the night before an auditor came. It served no real purpose other than to pass an audit or hood-wink a customer. With Plexus Online, the Control Plan is an integral part of production, and actually controls the process on the shop floor. The quality documentation is not an after-the-fact nuisance. It is the mechanism by which the parts are made.

With Plexus Online, operators on the shop floor use a touch screen called the “Control Panel.” This acts as a sort of “operator portal,” providing the operator an easy-to-use interface with everything he needs to do his job properly. The Control Panel provides information to the operator, but it also controls incoming source material, outgoing production, validates tooling, and foolproofs the process.

Via the Control Panel, the information in the Control Plan is displayed as easy-to-use operator checksheets that provide setup instructions, process instructions, measurement data collection, and SPC. The checksheets also support pictures and drawings, color coding, and other features to make them even more effective.

“The Plexus Online system prevents us from working on a part unless everything is setup properly, the correct raw material components are present, and all our inspections are done,” said Bytec's quality manager. ”I know it sounds simple, but it's a big reason why we are not making the mistakes of our competitors.”

Barcode labels and handheld scanners are also an important part of every Plexus Online implementation, enabling operators and material handlers to quickly and efficiently move materials around the shop floor.

The combined capabilities of process control and traceability have allowed Bytec not only to produce the UCB without major problems since the part was launched but also to make multiple design changes that have radically improved the part's performance.

Next Steps

Having succeeded with the initial goal for the UCB, Bytec and the Tier One now are planning the next phase of the project, which involves tying the UCB serial number to the OEM's Vehicle Identification Number (VIN).

In addition, Bytec has recently resourced the components of the UCB, including the rubber provider, to companies that also utilize Plexus Online. This will allow the UCB components to be traced, not just within Bytec and the Tier One, but across the extended supply chain.

With the success of this first traceability project, Bytec's OEM and Tier One customers are indicating more business will be forth coming.

Most recently, Bytec has decided to move forward with a full implementation of Plexus Online across its entire organization so that Plexus Online handles all their manufacturing lines and manages all aspects of their business - from shop floor to top floor.
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