Specifications: the bane of buyer and seller.

Specifications: The Bane of Buyer and Seller

The current state of specifications is chaotic. The belief seems to be that anything on paper is better than nothing at all. This is not true. If there is no validation of the specification, or if the margin of testing error is too great, then the specification is worse than useless-it is misleading. Specifications must accurately predict the performance of the product or service supplied.

This is the first of two articles that deal with the difficult task of establishing specifications. It is the intent of this effort to create guidelines that will make the approach to writing specifications uniform, thereby minimizing the risks related to invalid and/or immeasurable specifications.

The basic goal of specifications is to communicate a detailed description of a product to interested parties. Successful communication lets groups express and exchange ideas and permits each group to get a desired message across or to accomplish a specific task, while ineffective communication techniques lead to a confused and chaotic state of operation.

Who Sets Specifications?

There are two kinds of consumer: the one who knows exactly what is needed and the one who just has an idea of what is needed. When it comes to communicating or setting specifications, each has a different role in the exchange of ideas that leads to formal specifications.

Though two distinct types of consumer have been defined, there is still one specification common to them both and also to the supplier. That is fitness for use. Fitness for use is the ultimate goal, but is very difficult to quantify to the individuals involved with the production, sale, purchase and use of a specific product. This is why effective specifications should be used to communicate the knowledge of "fitness for use." Viable specifications are the main link that keeps the chain of commerce together.

The first type of consumer, the customer who is very knowledgeable about his process, makes the decision as to who sets specifications very easy--the customer himself will. The process of determining specifications varies depending on the organization's size and structure.

Typically, the process of putting together a product starts in the research and development or design department. There, the needed product is studied and begins to take shape along with the information required to develop initial specifications.

Data from these efforts are then evaluated by other concerned departments, such as production, material handling and quality assurance. At this level, it is imperative that all concerned departments evaluate the product and determine which specifications are functional and which are nonfunctional.

Once everything is understood and agreed upon, the specification package is complied and forwarded to Purchasing for final evaluation. This package may contain all or some of the following components: . title; . historical background; . definition; . physical characteristics; . special information; . list of contents; . methods of testing and criteria; . relevant authorities; . reliability and maintainability; . role of product packaging and protection; . references; . scope for acceptance; . pertinent conditions.(1)

The specifications are then forwarded to the vendor's marketing and development and design groups for feasibility analysis. At this time, both organizations, vendor marketing and customer purchasing, should meet to discuss background information concerning the nature of the product and how it is to be utilized.

Here, both customer and supplier can learn something about each other, exchange ideas on functional and nonfunctional parameters and resolve critical vs. noncritical specifications. Honest and open communication must exist if the common goal of fitness for use is to be achieved.

The second type of customer, who cannot supply exact specifications, must rely upon the vendor to provide specifications. The supplier must provide background data and specifications to the customer for his informational educational use. In this situation, the supplier does the initial development, design and manufacturing feasibility work. Again, both parties should meet to exchange ideas. (1)Juran, J.M., Quality Control Handbook, 3rd ed., pp. 8-59, New York: McGraw-Hill Book Co (1974).

In both consumer cases, when specifications are finalized and all other aspects are covered, a viable purchasing document can be issued. However, it does not end here. The lines of communication must not be broken once the agreements are finalized.

Systems involved in the production process are subject to change and customers do evolve additional requirements as more knowedge is gained relative to the product and its use. Regardless, if the communication channels remain open then potential problems are avoided.

Once the lines of communication are established, a complete understanding of the product in question and its use is necessary in order to determine true product specifications.

Fitness for Use

Fitness for use is an expression used throughout this series. Specifications are intended to provide a detailed description of a product that is fit to use by the customer.

If you ask a major league pitcher to define the most desirable characteristics of a baseball (his definition of fitness for use for the ball), he might say it should go 100 mph on all pitches, be easily controllable and be impossible to hit out of the infield. If you asked a batter for his definition of fitness for the same baseball, the answer would be very different; most probably it would be the exact opposite of the pitcher's definition.

The point here is that fitness for use is a user-defined term. When the user is your customer, you should be aware of his definition of fitness for use. A product may meet all the written specifications, but not the customer's definition of fitness for use.

An example of this is casting hardness. The maximum Brinell on a part allowed on the blueprint might be 269 with a typical range 217-269. You might ship numerous parts at 255 and 269. None are out of specification, but the customer is complaining about poor tool life.

What does the customer do next? He buys from a supplier who gives him a product that is still within specification but at a lower range, one that meets his definition of fitness for use.

Let's carry this discussion a bit further. Let's suppose that the lower end of the specification is marginal as to the end product use. That is, some parts produced at the lower end of the hardness range might fail under extreme loading conditions in the field. What is the end user's definition of fitness for use? The end user wants a product that does not fail under any circumstances and he does not care about tool life.

Whom do we satisfy--the machinist or the end user? The answer is simple--both! Casting producers and machinists alike have a financial responsibility to the end users to provide products that meet their definition of fitness for use. Also, they have a responsibility to themselves and to each other.

That responsibility begins with open communication to discuss the requirements of the product being used, defining the meaning of fitness for use from each other's perspective and deciding on a rational operating/product specification that satisfies everyone.

Specification Characteristics

Specification characteristics must be relevant to the end-use of the product. Products are bought for a purpose. Therefore, the purchaser and producer must jointly define this purpose and determine which product characteristics best measure the desired performance criteria.

For example, high-temperature coke is used as a fuel and for metallurgical purposes in the foundry industry. It is screened by the coke producer and purchased by foundries according to size, e.g., + 6 in.; 5 in. x 9 in.; 4 in. x 5 in.

Coke sizing appears to be of prime importance to most foundry operators. They purchase coke based on a minimum bottom size and/or a maximum top size. Does size make a difference? If so, does a minimum bottom size and/ or a maximum top size truly define its fitness for use? Without this knowledge, how can a specification be developed that describes the foundry coke size requirements of the cupola?

Maybe a closely sized coke product is better for foundry operators; 4 in. x 6 in. coke could be specified instead of + 4 in. coke. Both products specify a 4 in. bottom size and will yield the same amount of coke under 4 in. However, the size variations in the + 4 in. coke will be greater than the sizes found in the 4 in. x 6 in. coke. Should the foundry continue to specify + 4 in. coke, or is the more closely sized 4 in. x 6 in. coke more fit to use in his case?

In addition to size, specifications for coke also are based upon certain physical and chemical properties. These coke characteristics include moisture, volatile matter, ash, fixed carbon, sulfur and strength. Unfortunately, there is little real knowledge as to the correlation of these or other coke properties with the behavior of coke in the cupola or other combustion device.

Such correlations are greatly needed in order to determine meaningful specification characteristics for coke. Likewise, in any industry, it is necessary to understand the properties of your supplies as they relate to your final product.

The preceding example is just one of countless examples of frustrating situations that must be resolved in the ongoing effort to produce credible specifications. Manufacturers and their suppliers must work together to determine the product properties that are critical to the customer's operation.

If the characteristics and properties that require measurement can be more precisely defined, then the customer and supplier will be happier with their relationship. Customers and suppliers both should be willing to establish a good working relationship in order to determine which characteristics require specifying.