Production errors

Start-Up Checks. This subgroup of checks forms the last line of defense against errors in the production operation. If an error or skew situation is found prior to bottling, the situation is usually correctable however, product errors found after the product has been bottled nearly always result in dumping and total loss of product, package, and labor. 

Is a 72 h field alert needed A medical device report (MDR) Biologic product errors and accident (E/ A) report ... 

Errors in chemical analyses are seldom this dramatic, but they may have equally serious effects, as described in this chapter. Among other applications, analytical results are often used in the diagnosis of disease, in the assessment of hazardous wastes and pollution, in the solving of major crimes, and in the quality control of itiSustrial products. Errors in these results can have serious personal and societal effects. This chapter considers the various types of errors encountered in chemical analyses and the methods we can use to detect them. 

A production error leads to the sulfide being placed in a 950-L vessel with insufficient oxygen. The partial pressure of Oo is 0.64 atm and the total pressure is initially 1.05 atm, with the balance N2. The reaction is run until 85% of the O2 is consumed, and the vessel is then cooled to its initial temperature. What is the total pressure and partial pressure of each gas in the vessel ... 

Fig. 2 Effect of time on the hydrothermal treatment of Kraft pine lignin A. a The yields of residue at 300 °C and 374 °C. b The yields of gases at 300 °C and 374 °C. c The yield of gaseous products. Error bars represent standard deviations calculated fiom the data obtained fiom at least three repeated experiments...

It is advantageous to choose a layout that yields more than one microchannel per device. An example with three parallel channels is displayed in Fig. lb. This ensures that an intact channel is available for the experiment, even if one (or two) of the channels are damaged by production errors. 

Organizational stress, exhibited by absenteeism, poor productivity, errors, high accident rates, burnout, etc. 

NOTE 2. Measurement error should not be confused with production error or mistake. 

Error, Fig. 3 Production error, tolerance zone, and measurement uncertainty. Measurement 1 product is within specification measurement 2 fulfilling of specification not proven measurement 3 product out of specification... 

If we have another look at the definition of error (see definition), we should pay some attention to NOTE 2 of the VIM definition. This note points to the fact that error is also used outside of metrology, e.g., as production error, which we might define as product out of specification, e.g., a ground cylinder with diameter of 20.005 mm, whereas the specification asks for a diameter of 19.997-20.003 mm (dia. 20.000 0.003 mm). 

This concept is illustrated in Fig. 3. For evaluating any production error (or product error), we need a nominal value and the tolerance, as well as the measured quantity value plus/minus the measurement uncertainty. 

In measurement 1, measured quantity value plus/minus measurement uncertainty is fuUy within the tolerance limits. Here no production error is present, the product conforms to the specification. 

In measurement, 2 measured quantity value plus/minus measurement uncertainty is partly out of the tolerance zone. Therefore, it is not sure if there is a production error. It is tmcer-tain that the product fulfills the specification. Measurements shall be carried out with smaller measurement uncertainty. 

In measurement 3, measured quantity value plus/minus tolerance is fully outside the tolerance zone. Therefore, we obey a production error. 

For mechanical parts, we group production errors in form error (e.g., flatness error, roundness error, roughness error), size error (e.g., diameter error, pitch error of a screw), position and orientation error (e.g., distance error between two nominal parallel planes, squareness error, coaxiality error). 

The solubility product principle can only be strictly applied to equilibrium conditions, although it has often been used to explain such precipitations as those encountered in qualitative analysis by the traditional wet-test methods. However, these sudden precipitations do not take place under anything like equilibrium conditions and the fact that reasonably successful predictions can usually be made is mainly due to the enormous excess ionic concentrations (supersaturations) generated compared with those required by the corresponding solubility products. Errors of magnitude of 10 —10 per cent have been estimated (Lewin, 1960) for such calculations and these clearly swamp other variations such as neglect of solute activity coefficients, complex ion formation, etc. 

A CAPA system does not only lead to quality improvement, but also to fewer (product) errors and thus to cost reduction. For the implementation of a CAPA system, forms, a (excel) database, or even especially developed software systems can be used. 

It is important to maintain a set of monitoring records that are recorded (preferably in ink) by the operator taking the measurement and at the time the measurement is taken. These records should be reviewed by a supervisor within a couple of days and before any product has left the facility. A frequent review of these records can identify possible production errors while corrections are still possible. 

The note 2 refers already to the problem with random hardware faults and systematic failures. The cause of an error in a system is never only related to random hardware faults, the cause for a random hardware fault is often already a systematic fault such as wrong selection of the part, wrong estimation of environmental impacts, production errors etc. That means all quantitative methods rely on systematic analysis, where the quantification could only consider as an indication or as a metric for comparison or balancing of the architecture or design. In other standards those approaches are considered also as semi-quantitative analysis. Furthermore, the question is if these methods are only the kind of representation of the result of the analysis rather than the indication for the analysis itself. 

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