Sampling acceptable quality level

When using the defect-detection approach to quality control certain problems develop. Inspection does nothing to improve the process and is not very good at sorting good-from-bad. Also, sampling plans developed to support an acceptable quality level (AQL) of 5%, for example, say that a company is content to deliver or reject 5% defects. 

Acceptance criteria means the product specifications and acceptance/rejection criteria, such as acceptable quality level and unacceptable quality level, with an associated sampling plan, that are necessary for making a decision to accept or reject a lot or batch (or any other convenient subgroups of manufactured units). 

As with other packaging components, the incoming tests and specifications of metered valves, inspection attributes, and AQLs (acceptable quality levels) will need to be coordinated with the supplier. The valve should be considered as a critical package component and have incoming performance tests, such as spray weights and weight loss [13,14], The performance test could be conducted on a sample of the valve lots from either scale-up or pilot trials before the validation lots are prepared. This information may also be available for each lot from the supplier. It is recommended that each test shown in Table 3 be conducted on at least three valve lots as part of the validation program. 

Acceptable quality level is related to the quality required in the product. The acceptable quality level is the maximum percentage nonconformity that, for the purpose of the sampling inspection, can be considered satisfactory as a process average. ... 

The acceptable quality level has a particular significance in the design and use of acceptance sampling plans, e.g. ISO 2859 - 1. 

Two sets of standards are set for empty capsules, analytical and functional. Capsules, like all other pharmaceutical preparations, must comply with cGMP norms and must be made of materials that comply with pharmacopeial chemical and microbiological standards. However, these tests do not indicate whether a capsule will run well on a filling machine. Series of functional tests are applied by the manufacturers. The critical dimensions of a capsule (the lengths and diameters of the caps and bodies) are checked. It is a continuous production process, and there will be a very small proportion of visually defective capsules. Standard statistical sampling methods are used to estimate quality from samples. The manufacturers and users agree on acceptable quality levels (AQL). The faults are... 

Acceptable quality level (AQL) inspection acceptance criteria are applied to the inspections. Visible foreign particulate matter is considered a critical defect. Thus, AQL levels (the greatest percentage of defective units still acceptable for release) are 0.25-1.0% of the lot size. Consult the American National Standards Institute/American Society for Quality Z1.4 guideline for more detailed information on AQL sampling. The drawbacks of manual inspection are that it is prone to human error and is subjective. 

Glove quality standards have been established by the FDA based on a sampling scheme and a quality assurance test known as the 1000 mL water leak test described in the Code of Federal Regulations, 21 CFR 800.20 [127]. The Final Rule was published in December 12, 1990, and became effective March 12, 1991. The acceptable quality level is a maximum failure rate of 2.5% for surgeons gloves and of 4.0% for patient examination gloves as determined in this water leak test. 

ISO 2859-1. 1989. Specification for sampling plans indexed b acceptable quality level (AQL) for lot-by-lot inspection. 

Let s look at right quality the level the customer wants or better if possible. Most customers want zero defects. The traditional method was to use a random sample and develop an acceptable quality level (AQL). A sampling plan was developed and then the sampling standard tables were looked at to determine if the lot should be accepted or rejected. Using the acceptable quality level indicated that the customer was willing to accept some defects. In most cases today this method is not used. With the advent of Six Sigma the levels of acceptability have come way down, approaching zero defects. 

The Acceptable Quality Level (AQL) is the maximum percentage of defectives or the maximum deviation from label claim that is acceptable as a long-term average. It is the poorest quality level for the supplier s process that a consumer would consider to be acceptable as a process average. AQL is a property of the supplier s manufacturing process, not a property of the sampling plan. 

A sampling plan for attributes is a method to overcome this problem. An example of such a plan is the Accepted Quality Level system (AQL) (See Sect. 24.5.4. for a more complete description of AQL and Sect. 20.4.5 for a statistic background). In order for the AQL system to be successful an extensive and statistically planned random sample has to be selected. The defects that are found are classified into levels, for example critical, major, minor. Within each level the system defines an acceptable quality level . When a quality level is exceeded, then a batch should be rejected. This method of testing requires time and expertise. Sampling has to be performed from a large number of containers from the same batch. Within the pharmaceutical industry it is often necessary for such tests to be carried out by the container manufacturer. For smaller enterprises such as pharmacies quality control can be undertaken by the wholesaler or an independent laboratory. Within a (hospital) pharmacy the quality control is often limited to a visual comparison to reference samples and a check of the presence of the supplier s statement that the containers comply with the agreed specifications [46]. 

The AQL-system is a sampling and assessment system frequently used to check cOTitainers. It is a type of attribute assessment, see Sect. 20.4.5 for statistical background. AQL means Acceptable Quality Level. The AQL-value is the percentage of rejected units accepted by a supplier or buyer to approve the crmcemed batch. Tables are available which describe, for a certain batch size N and an agreed AQL-value, how large the test sample n should be and how many units of that sample are allowed to show a specific defect The AQL-system classifies defects in classes ... 

Acceptance Testing. With increased emphasis on quality control and quality assurance, raw materials or intermediates are subjected to a series of tests of relevant properties to ensure that they match the producers specification. The acceptance quality level, which is the percentage which is acceptable to the buyer, is usually specified, and compliance checked by testing and statistical analysis of the results. BS 3921 lays down a detailed sampling scheme for building bricks. 

Attributes. Qualitative characteristics of products, whose presence or absence is subject to inspection to assess the acceptance quality level of a sample. (Inspection by variables involves numerical measurement) BS 1902 Pt 3.13 relates to the attributive properties of corner, edge and surface defects in refractories. See acceptance testing. Attrition. Particle-size reduction by a process depending mainly on impact and/or a rubbing action. 

In contrast to the requirements for enforcement methods and to ensure sufficient quality of the generated data, validation data should be submitted for all types of crop samples to be analyzed. However, matrix comparability and a reduced validation data set may be considered where two or more very similar matrices are to be analyzed (e.g., cereal grain). A reduced sample set may also be acceptable (two levels, at least three determinations and an assessment of matrix interference) provided that the investigated samples belong to the same crop group as described in SANCO/825/00 (see also Section 4.2.1). 

The rules for level I (screening) assays are shown in Table 13.1. An example of the type of samples where a level I assay could be used is the CARRS samples [85] that can be used for screening NCEs using a rat PK model [vide supra). The concept behind this assay is that it should use a small number of standards and a simple linear extrapolation. For level II assays (see Table 13.2) that might be used for discovery PK studies in preclinical species, a complete standard curve is required. In this case a complete standard curve is defined as 10-15 standards in duplicate assayed with at least five standards used in the final calibration curve. Neither level I nor level II assays require the use of quality control (QC) standards. When a compound is in the lead qualification stage, then a level III assay would be required. As shown in Table 13.3, the main distinction for level III assays is that they are required to include at least six QC standards. As described in Tables 13.1-13.3, these rules show the requirements for how an assay should be set up before the samples are assayed and then these rules describe the acceptance criteria for the assays after they have been performed. 

---