**2. Quality control**

A variety of methods exist to control the products or process quality. Seven statistical process control (SPC) tools are included such as plan, do, check, act (PDCA), quality function deployment (QFD), acceptance sampling, failure mode and effects analysis (FMEA), a design of experiments (DoE) and six sigma [2]. This chapter emphasizes the implementation of quality control in companies and categorizes the factors applying for quality control techniques, the techniques used in the implementation. The inspiring factors for the companies to relate quality control and tasks challenge by companies in implementing the quality control [3–5]. Laboratory facilities are an important constituent of quality health care. It can be employed efficiently at each level of health care system, involving point-of-care and primary health care testing. Results of the quality laboratory are requisite to support justify, monitor, treatment and clinical diagnosis, for the purposes of epidemiology, surveillance and control of disease at public health importance, and to deliver the initial warning of disease epidemics. This increases the accuracy of health evidence and endorses the national health planning effectively. The aim of establishing laboratory quality standards is to confirm the confidence of patients, increase the accuracy of test results, communities and clinicians in the importance of laboratory testing, and to update patient management [6]. Entirely laboratory activities might be subject to errors, and many studies have exposed that errors in the laboratory can appear in all the phases of diagnostic processes. The examples of errors that may occur in all phase

• Incorrect collection of specimen, inadequate quantity, improper labeling and transportation

• Incorrect procedures; non-adherence to internal quality control (IQC) or standard operat-

• Use of defective equipment, inappropriate use of an equipment

are given below.

40 Quality Control in Laboratory

**1.1. Pre-analytical phase**

**1.2. Analytical phase**

ing procedures (SOPs)

**1.3. Post-analytical phase**

• Incorrect test selection or test request • Incomplete request forms of laboratory

• Use of expired or substandard reagents

• Inappropriate reporting or recording

• Send the results too late to the clinician

• Inappropriate interpretation of the results

• Incorrect calculations, transcription or computation

• Incorrect storage and reagent preparation

Quality can be described as achieving customer requirement or specification, without any deficiency. A product is considered to be great in quality if it is working as reliable and expected. Quality control denotes to activities to confirm that produced articles are achieving the highest promising quality. Furthermost of tools and techniques to control the quality are statistical procedures. The techniques for the quality control can be categorized into the basic, intermediate and advanced level, although there is no unanimity amongst researchers about it. For example, Xie et al. [7] deliberate the DoE as an intermediary level technique while Antony et al. [8] classified that technique as advanced. Nonetheless, the contents are more significant rather than the classification. Amongst the basic techniques, SPC is a statistical method for supporting the supervisors, operators and managers to accomplish quality and to remove special causes of inconsistency in the process [9]. The early role of SPC is to stop rather than process deterioration or recognize the product, but Xie et al. [7] propose for its new role to vigorously identifying prospects for the improvement of the process. The foremost tools in SPC are control charts. An essential knowledge of the control charts is to analyze the hypothesis that there are few common reasons of alternative versus variability, that there are exceptional causes by continuously observing the process. The manufacturing company could avoid defect items to be administered in the subsequent stage and to take instant corrective action while the process exists to be out of control [10].

DoE and Taguchi approaches are influential tools for the development of product and process. Taguchi methods, for example, the purpose of manufacturing products or process that vigorous to non-desirable turbulences such as manufacturing and environmental variations. Though, the request of these two approaches by industries is inadequate [11]. Antony et al. [8] delineate the problems in the application including the inappropriate understanding of statistical ideas in the procedures; therefore recommend an approach for the implementation. Procedure ability study is an effective technique to examine the ability of a procedure to produce items that meet specifications.

The process gains fast raising attention because of increased utilization of the quality system (QS9000), where to take advantage of method capability study are demanded [12]. The outcome obtains from capability study may want some modification of process employing some other statistical technique, for example, DoE or SPC. Furthermore, Motorcu and Gullu [13] and Srikaeo et al. [14] conducted a capability study in which process capability production and stability machine tool were assessed and crucial procedure to diminish poor quality production was carried out employing other statistical methods.

Failure mode and effects analysis (FMEA) is a well-known technique to identify the point where precisely problems can take place as well as to urgencies feasible problems in the order of their difficulty [15]. This tool is valuable to troubleshoot problems in the process, i.e. process FMEA and to recognize problems in the product, i.e. design FMEA [7]. Additionally, six sigma is also a known statistical device for confirming the fault-free products via nonstop progress and six sigma application has been chiefly employed in manufacturing industry. However, use of six sigma in the software development is a case of the non-manufacturing industry [16]. The term six sigma instigated by Motorola as well as various motivated international organizations have fixed goal concerning a six sigma level of implementation [17].

Moreover, acceptance sampling is alternative statistical techniques that concluded whether to take or refuse a quota based on the information from the sample. The request for the approval of sampling permits industries to minimize the product demolition through examination and to raise the inspection capacity and efficiency. The request of getting sampling has been chiefly employed in manufacturing industry; however, Slattery [18] reported its application in non-manufacturing industry.
