Good standards are a given for consistent, profitable manufacturing and to achieve high-quality product. Good standards are a challenge to design. We have, on occasion, found ourselves in a position of having to meet an unachievable or inappropriate standard; perhaps you have also.

Some desirable and inter-related attributes of a good standard include:
Consensus
Appropriate Focus and Relevance
Practical and Achievable
Adaptable and Up-to-Date

Consensus
We are all a product of our background, including accustomed modes of production and process control. This is not in itself a negative. Certainly, if the product has historically performed successfully, if it continues to be successful, and if production is efficient and cost-effective, then we are operating appropriately. At the same time, with ever increasing pressures (costs, competition, performance, and regulatory), it is helpful to have standards developed by a consensus of thoughtful, productive participants.

Appropriate Focus and Relevance
Consensus standards tend to be relevant, encompassing without being too general, and sufficiently specific to meet the current and near-future needs of industry. Standards designed by a group have the advantage of collective wisdom. Such standards tend to avoid the problems associated with focusing too closely on a particular issue or on a particular product.

Running tests does not in itself appropriately control the process. As users of standards, it is important to maintain control, to continuously re-evaluate what standards and tests are employed. For example, one company had had problems of surface damage associated with breakdown of chlorinated solvents. The problem was controlled by monitoring incoming and in-use solvent for free chlorine. After decades, the process was changed; a non-chlorinated solvent was adopted. Unfortunately, the group continued to test for free chlorine, long after the chlorinated solvent was discontinued.

Suggestions to stop monitoring free chlorine fell on deaf ears. Many production people insisted the test was necessary, citing the terrific record of productivity and the low level of product failure. On the one hand, doing the test did no harm, in the sense that free chlorine would be unlikely in the non-chlorinated solvent. At the same time, the test needed to be changed. Unnecessary testing costs time and money. An irrelevant test provides a false sense of security. The new solvent needed to be monitored with a relevant test, one that could provide an indication of solvent cleanliness and stability.

Practical and Achievable
A useful standard has to be achievable by a range of companies. It must be realistic in terms of detection limits, sampling, and reproducibility. We are aware of situations where standards control the process without necessarily assuring process performance. It is not unknown for standards of cleanliness to be set so low, and with such low allowable variability in results, that the inherent variability of the test method is greater than the variability permitted by the standard.

In other situations, the required test may be so expensive that it cannot be readily performed by those companies who most need standards, particularly small to medium companies, that are developing new, innovative product. Sampling is another problem in good standards development. While replication is necessary for meaningful results, destructive testing in pentuplicate is not a realistic goal for small scale, diverse processes where the batch size is, say, four to seven.

Adaptable and Up-to-Date
Most, if not all, manufacturing processes are site-specific. A standard that only works for one company, for one process, is not particularly adaptable. One that is too broad becomes at best a guidance document. Balance is the key; and a consensus document is a good way to balance and to devise a standard with some degree of longevity.

Nothing lasts forever. In the classic parable “The Deacon’s Masterpiece or, the Wonderful ‘One-hoss-Shay’: A Logical Story,” Oliver Wendell Holmes illustrates the futility of devising a carriage (or, by analogy, a standard) that would last forever. The carefully crafted Shay is built at the time of an earthquake; and certainly standards have been known to be established in response to some catastrophic failure. The carriage lasts exactly for a century, and then, completely disintegrates to dust (An on-line copy of the poem is at http://eir.library.utoronto.ca/rpo/display/poem1028.html). In the same way, cleanliness and contamination control standards are a product of their time, or their manufacturing environment. Even exquisitely crafted standards don’t last forever; they have to be updated.

Conclusions
Standards are a necessity, and they are a community activity. We say this, with the awareness that attendance at standards meetings have been known to promote a sound, restful nap. It’s worth participating and staying awake!

Finally, while standards provide a measure of assurance, given the diversity of cleaning and surface preparation processes as well as the number of variables in any given process, there is no substitute for a well-designed, carefully monitored process.

 

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