Out of specification

An example of procedures found by performing a job task analysis would be rework procedures. Occasionally, out of specification product is produced which can be reworked in the process. This subcategoiy of normal operations phase procedures may require special consideration. While rework can be a straightforward operation, it could have safety consequences if done improperly. 

Are appropriate directions for reacting to out-of-specification situations documented m standard operating procedures ... 

A value of Cp = 1.33 would indicate that the distribution of the product characteristics covers 75% of the tolerance. This would be sufficient to assume that the process is capable of producing an adequate proportion to specification. The numbers of failures falling out of specification for various values of Cp and Cp can be determined from Standard Normal Distribution (SND) theory (see an example later for how to determine the failure in parts-per-million or ppm). For example, at Cp = 1.33, the expected number of failures is 64 ppm in total. 

Waste streams Cater for routine and emergency, safe discharge of all waste streams, e.g. atmospheric venting, possibly after treatment, discharge of liquid effluents including out-of-specification streams, discharges of particulate or bulk solids... 

Approvals and Authorizations Appropriate delegations have been established, and authorities are cieariy established for approval of specific routine operations and non-routine or out-of-specification operations. Variance procedures are defined. Approval levels are commensurate with the importance of the task. Appropriate resources are authorized. 

Most faults are attributed to poorly machined surfaces causing out-of-specification tolerances, although defective material failures also occur. Inadequate material hardness and poor strength factors contribute to many premature failures. Other common causes are improper coupling selection, improper installation, and/or excessive misalignment. 

Testing and QC are discussed but often the least understood. Usually it involves the inspection of materials and products as they complete different phases of processing. Products that are within specifications proceed, while those that are out of specification are either repaired or scrapped. Possibly the workers who made the out-of-spec products are notified so they can correct their mistake. 

The usual response to the apparently high and out-of-specification result is to correct the problem by increasing boiler blowdown. The net result is an unnecessary waste of BD water and the heat associated with it. Consequentially, there is an unnecessary increase in fuel consumption. 

Feedwater contamination problems may also occur where ion-exchange plants are employed for dealkalization or demineralization/ deionization (DI) processes. Where such equipment is used, however, it is common for some form of continuous monitoring to be provided, perhaps in association with an audible alarm to provide a warning of out-of-specification FW. 

Conductivity, sodium, pH level, silica, ammonia, hydrogen, carbon dioxide, iron, copper and other parameters are typically measured, with alarms and other devices fitted to warn if the steam or water purity goes out of specification. 

Warning One should realize that a dishonest analyst can willingly shift the result within a range of several percent of the true value, which would certainly suffice to make a slightly out-of-specification product suddenly conform to these limits. This could be accomplished with the following... 

X) duplicate measurements in same 0.2% class, single results in (U) Content Uniformity or (R) lOx Repeatability test ( ) out-of-specification measasurement,... 

Investigating Out of Specification (005) Test Results for Pharmaceutical Production, FDA Draft Guidance for Industry (J IGUIDANC 121DFT.WPD) dated 9/4/98. 

The actual data, including replicates, mean, and range, in tabular form should follow, accompanied by a brief discussion of the data. It is important to explain any out-of-specification data. Statistical analyses for all parameters, which lend themselves to such analyses along with conclusions, should be incorporated into the document at this point. These statistical analyses should be accompanied by the results of experiments conducted to determine the poolability of batches, or commonality of slopes and intercepts of individual batches. Graphs of these data should be included as part of the documentation. 

Extrusion processes can generate several types of scrap, including out-of-specification material, material generated when the process is not running at steady state, and edge trim when sheet or film is trimmed to the required width. In extrusion, the scrap can be reintroduced to the material stream and reincorporated into the manufactured products. As with injection molding, the form of the scrap often differs substantially from the starting resin. 

Control of product gauge is of considerable importance for the majority of products produced from calenders and various means have been used to achieve this from the early days of the machine. Inaccuracies in gauge on calendered products can not only mean out of specification goods being produced, but also one can be giving away free of charge considerable quantities of expensive compounds (unless the product is sold by weight, of course). 

Lastly, the need for potential trouble shooting bulk samples should be agreed to facilitate any out-of-specification (OOS) investigations (Worsham, 2010). 

Samples of intermediates and finished products taken for analysis are recorded, stating the time, date, and conditions for these samples. Deviations in operating conditions and out of specification (OOS) conditions in samples are reported and investigated. Figure 9.2 shows a mechanism for production and in-process controls. 

Out-of-Specifications There are insufficient investigations to determine the root cause of problems and issues are not closed in a timely manner. Product Sterility The tests performed are superficial and not validated. Environment Monitoring Personnel are not monitored, there is inadequate monitoring, microorganisms are not monitored, there is no... 

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