Cost of nonconformity

Petrochemical processes require smaller reactors than used in refineries. Chemical reactors are sized in the 50 to 250 cu.ft. range. Orders for replacement catalyst usually range from 10,000 to 50,000 lbs, but there are many different process applications. Catalyst quality is becoming more important than in recent years as many industries attempt to reduce the cost of nonconformance and improve the quality of manufactured goods. 

Cost must be understood in the context of quahty. If quahty means conformance to requirements, then quality costs must be understood in terms of costs of conformance and costs of nonconformance, , as illustrated in Figure 19-1. In industrial terms, costs of conformance are divided into prevention costs and appraisal costs. Costs of nonconformance consist of internal and external failure costs. For a laboratory testing process, calibration is a good example of a cost incurred to prevent problems. Lhcewise, quality control is a cost for appraising performance, a repeat run is an internal failure cost for poor analytical performance, and repeat requests for tests because of poor analytical quality are an external failure cost. 

Figure 19-1 The cost of quality in terms of the costs of conformance and the costs of nonconformance to customer requirements. (From Westgard jO, Barry PL, Cost-e/fect/ve quality control Managing the quality and productivity of analytical processes. Washington DOAACC Press, 1986.)...

This requirement can impose unnecessary constraints if you take it literally. Many activities in quality plans and procedures are performed to give early warning of nonconformities. This is in order to avoid the losses that can be incurred if failure occurs in later tests and inspections. The earlier you confirm conformance the less costly any rework will be. 

The corrective action requirements fail to stipulate when corrective action should be taken except to say that they shall be to a degree appropriate to the risks encountered. There is no compulsion for the supplier to correct nonconformities before repeat production or shipment of subsequent product. However, immediate correction is not always practical. You should base the timing of your corrective action on the severity of the nonconformities. All nonconformities are costly to the business, but correction also adds to the cost and should be matched to the benefits it will accrue (see later under Risks). Any action taken to eliminate a nonconformity before the customer receives the product or service could be considered a preventive action. By this definition, final inspection is a preventive action because it should prevent the supply of nonconforming product to the customer. However, an error becomes a nonconformity when detected at any acceptance stage in the process, as indicated in clause 4.12 of the standard. Therefore an action taken to eliminate a potential nonconformity prior to an acceptance stage is a preventive action. This rules out any inspection stages as being preventive action measures - they are detection measures only. 

Additionally, contracts may be negotiated for payment or milestones. This challenges the vendor to keep to the time line and complete the tasks in order. Incentives for completing work early can be included. Penalties for nondeliverables or the cost for nonconformance can also be defined. This provides an incentive for the vendor to reach and maintain an appropriate level of compliance. 

The cost of the assembled PCB continues to increase because of density, complexity, and rising material and component costs. The value added to the PCB can be 10 to 20 times the cost of PCB. If it is found that a nonconforming PCB is the cause of failure, the total cost of the assembly process is likely to be passed on to the PCB manufacturer. 

Furthermore, a joint buyer—supplier quality program can reduce the amount of defective product and service instances. The cost of rejecting materials and shipments for noncompliance increases costs related to transportation and testing, among others. Working with suppliers can reduce the amount of defective and nonconforming products and services. 

Many organizations use a Nonconformity Report to deal with the remedial action and a Corrective Action Report or Request (CAR) to prevent the recurrence of one or more nonconformities. In this way you are not committed to taking action on every incident but on a group of incidents when the action and its cost can be more easily justified. 

The problem is that hydrogen, even at 10,000 psi (or 690 bar), requires five to ten times the volume of today s gasoline tank, depending on the fuel cell vehicle s real world efficiency. Packaging volume is compromised even further because pressurized tanks require thick carbon fiber walls and are, therefore, nonconformable. Moreover, they may cost several thousand dollars more than a conventional gasoline tank. 

In the final analysis, market price and sales volume are functions of the quality standards offered and the buyer s degree of confidence that the product will conform to the standards. Maintenance of buyer s confidence requires inspection to screen out all nonconforming products, or control over variability of quality during production and distribution to a degree where few, if any, products fail to meet the standards. Screening inspection of the finished product cannot improve quality it merely serves to segregate unacceptable from acceptable product, and results in loss of production capacity and costly waste and salvage. The second consideration provides the only sound basis for quality control in frozen food production and distribution. It operates on the old principle that an ounce of prevention is worth a pound of cure. ... 

Ultimately, this effect might drive the pad out of specification (either from rapid wear or from nonconformity to MRR targets) and become a fundamental source of consumable costs. Only compensating solutions that are or can be programmed to change with time (based on number of wafers processed) will be able to extend the useful life of the pad. 

To iUustrate some common misconceptions, a few examples of compliant and noncompliant industrial-type components are discussed in the next sections. Fault-tolerant components, that have been EU type-approved for proper classification, such as positive opening, guarded actuator, redundancy, cross-monitoring, or fault detection, are preferred and in some cases mandatory. Testing nonapproved components (CE is not an approval) to verify their conformity or nonconformity is the higher risk (of failure) alternative and usually costs considerably more time and money. 

Since 100 percent inspection is generally both inefficient from a cost standpoint and ineffective in screening out nonconforming products, it should normally be considered only as an emergency measure and should not be established as a permanent feature of the process. The above criteria are minimum acceptable levels and should be considered as starting points for continuous improvement. 

During specific projects, it is common to see quality control performed on the worksite on lots sent by the manufacturer. This type of control is generally carried out by a third party mandated by the client or an engineer mandated by the client. In a case where nonconforming materials are found on the worksite, the plans and specifications usually specify the terms of replacement for the material, and related penalties. This sort of event is often costly for the client and the manufacturer, so it is in the interest of geotextile producers to ensure the quality of their products and ensure conformity in the factory before they are sent. 

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