Technology & Engineering
Quality Control
Quality control is a process that ensures products meet specific standards and requirements. It involves monitoring and testing products during and after production to identify and address any defects or deviations from the desired quality. By implementing quality control measures, companies can maintain consistency and reliability in their products, ultimately leading to customer satisfaction and trust.
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10 Key excerpts on "Quality Control"
eBook - PDFFactory Operations
Planning and Instructional Methods
- Richard Crowson(Author)
- 2005(Publication Date)
- CRC Press(Publisher)
When carried on throughout the whole process, we have the process control necessary to assure delivery of a quality product satisfying the ultimate customer’s expectations. The aim of the Quality Control (QC) program should be prevention of defects by improvement and control of processes in all aspects of the business. Regular moni-toring of the process will inevitably result in steady improvement through timely process adjustment and result in a corresponding reduction in cost. The following subchapters will provide greater insight into the techniques that have proven to be effective in reaching this goal. 6.0.1 Additional Reading Feigenbaum, A. V., “Total Quality Control,” Harvard Business Review, November–December 1958. Juran, J. M. and Gryna, F. M., Quality Control Handbook, 4th ed., McGraw-Hill, New York, 1988. Shuster, “Profound Knowledge: Source, Character, and Application,” in Proceedings of the 1st International Symposium on Productivity and Quality Improvement, Industrial Engineering Management Press, Norcross, Ga., 1992. Transition from Development to Production, Department of Defense Handbook on Manufac-turing Management, 2nd ed., Defense Systems Managements College, Fort Belvoir, Va., 1984. Control of Quality 263 6.1 QUALITY ENGINEERING AND PLANNING 6.1.1 Introduction to Quality Engineering and Planning The quality engineering and planning function provides the technical and admin-istrative guidance necessary to plan the overall quality initiatives for the company, to assist in their implementation, and to oversee achievement of the desired objec-tives and goals. Companywide interface and collaboration with all organizational elements is required for the successful accomplishment of this task. The planning function is a key part of quality engineering and planning responsibility.
eBook - PDFQuality Control for Profit
Gaining the Competitive Edge, Third Edition,
- Ronald H. Lester, Norbert L. Enrick, Harry E. Mottley Jr.(Authors)
- 1992(Publication Date)
- CRC Press(Publisher)
1. Attainment of quality at budgeted levels of cost. 2. Effective maintenance of quality. 3. Impartial measurement and reporting of quality. ORGANIZATION OF THE Quality Control DEPARTMENT An example of the Quality Control Department under Total Quality Control is illustrated in Fig. 2-4. Depending on the plant size structure, the nwnber and assignment of process engineers varies. In fact, in a small plant the duties of the process engineer may be absorbed by the Quality Control manager. TOTAL QUALITY AND CONTINUOUS IMPROVEMENT 21 MANAGER Quality Control QUALITY INfORMATION SECRETARY ANAL YST I I I 1 I I SUPERVISOR PROCESS PROCESS PROCESS SUPERVISOR CHIEF ENGINEER ENGINEER ENGINEER PRODUCT INSPECTOR MATERIALS DEPARTMENT DEPARTMENT DEPARTMENT TESTING LABORATORY 1 2 3 LABORATORY I I I I I I COMPONENT LABORATORY PROCESS PROCESS PROCESS LABORATORY PART TECHNICIANS TECHNICIANS TECHNICIANS TECHNICIANS TECHNICIANS INSPECTORS Figure 2-4 Typical Quality Control organization. QUALITY DEPARTMENT RESPONSIBILITIES AND ACCOUNTABILITY Responsibilities for each person and job in the department are broken down in terms of discrete, measurable units. These units refer to the control of produc-tion departments, product lines, or combinations of departments and lines. What is important is that there be responsibility for quality and the costs of quality. Moreover, the responsibility must be total, in the sense that all individual units should be encompassed by the program. Responsibility is divided as follows: 1. Process Control Engineer. Implements the quality planning in the fac-tory operation for a specific area of responsibility. 2. Quality Control Engineer. Performs Quality Control for a specific area of responsibility. 3. Quality Systems Engineer. Integrates quality planning for each area into a total quality system. 4. Advanced Quality Control Engineer. Performs advanced Quality Control based on long-range forecasts of quality needs.
- Victor E. Sower(Author)
- 2015(Publication Date)
- Wiley(Publisher)
Quality Technician’s Handbook. New York: Wiley. Griffith, G. (2003). The Quality Technician’s Handbook. Upper Saddle River, NJ: Prentice Hall. ‘‘Quality Glossary.’’ (2002). Quality Progress 35(7), July 2002, 43–61. Traver, R. W. (1962). ‘‘Measuring Equipment Repeatability–The Rubber Ruler.’’ 1962 ASQC Annual Convention Transactions. Milwaukee, WI: ASQC Quality Press. C H A P T E R T E N Statistical Process Control CHAPTER OBJECTIVES After completing this chapter, the reader should be able to: discuss the two types of variation and who has the responsibility to address each type; explain the concept of the control chart; identify out-of-control signals on a control chart; determine when it is appropriate to reevaluate the control limits on a control chart; select the appropriate control chart for specific applications and data types; construct variable control charts: x-bar, range, S, individual/moving range, and Delta charts; construct attribute control charts: p, np, c, and u charts; and select the appropriate measure for process capability and assess the capability of the in-control process to meet specifications. Quality as a concept can be subdivided into quality of design and quality of con- formance. Quality of design is determined by the extent to which products and services are designed with the needs and desires of the customers in mind. Quality of conformance is determined by the extent to which the intent of the designer is actually built into the product or service. Statistical process control (SPC) is concerned with quality of conformance. Organizations that have properly designed their products or services (i.e., quality of design is assured), and who use SPC to assure quality of conformance can answer the question ‘‘How are things going?’’ very simply and precisely. If things are going very well, it means that all processes are capable and are operating in control.
eBook - PDFStatistical Quality Control
A Modern Introduction
- Douglas C. Montgomery(Author)
- 2014(Publication Date)
- Wiley(Publisher)
Techniques such as control charts can be used to monitor the process output and detect when changes in the inputs are required to bring the process back to an in-control state. The models that relate the influential inputs to process outputs help determine the nature and magnitude of the adjustments required. In many processes, once the dynamic nature of the relationships between the inputs and the outputs are understood, it may be possible to routinely adjust the process so that future values of the product characteristics will be approx- imately on target. This routine adjustment is often called engineering control, automatic con- trol, or feedback control. We will briefly discuss these types of process control schemes in Chapter 11 and illustrate how statistical process control (or SPC) methods can be successfully integrated into a manufacturing system in which engineering control is in use. The third area of Quality Control and improvement that we discuss is acceptance sam- pling. This is closely connected with inspection and testing of product, which is one of the ear- liest aspects of Quality Control, dating back to long before statistical methodology was devel- oped for quality improvement. Inspection can occur at many points in a process. Acceptance sampling, defined as the inspection and classification of a sample of units selected at random from a larger batch or lot and the ultimate decision about disposition of the lot, usually occurs at two points: incoming raw materials or components, or final production. Several different variations of acceptance sampling are shown in Figure 1.6. In Figure 1.6a, the inspection operation is performed immediately following production, before the product is shipped to the customer. This is usually called outgoing inspection. Figure 1.6b illustrates incoming inspection—that is, a situation in which lots of batches of product are sampled as they are received from the supplier.
- Andrew Whyte(Author)
- 2014(Publication Date)
- CRC Press(Publisher)
109 Chapter 4 Quality Control in civil engineering projects Cost and time factors in civil engineering projects are somewhat easily quantifiable as dollars and days. Similarly, controlling and monitoring money and months on the job requires comparisons of value estimates ver-sus actual outgoings and progress. Quality Control in civil engineering work requires similar levels of mea-surable clarity. In civil engineering projects, quality can be guaranteed by a design team’s detailed drawings and comprehensive materials specifications, which adhere fully with current building codes as well as a builder’s full and complete compliance with these contractual documents. Q UALITY SYSTEMS IN CIVIL ENGINEERING Quality systems might be summarised as • Detailed checklists for civil engineering drawings and specifica-tions compliance • Checklists ensuring that prescriptive or performance require-ments are tested and met Quality Control and proof of structured quality systems must increas-ingly be embedded explicitly within the documentation to progress a civil engineering project. Often, a client’s tender-list of potential builders are required to have current quality system certification before even being allowed to submit a tender-bid for a project. Indeed, upon awarding a project to a preferred building firm, the stan-dard form of contract that is signed by the parties requires full compliance with clauses that stipulate that a contractor must have a conforming quality system in place and adhere to it specifically throughout the works.
eBook - PDF- Judith Clapp, Saul F. Stanten, W.W. Peng, D.R. Wallace, Deborah A. Cerino, Roger J Dziegiel Jr., Judith A. Clapp(Authors)
- 1995(Publication Date)
- William Andrew(Publisher)
Also described within this section are the checkpoints within the Software Quality Control program where the effects of application of the technique are reviewed, and replanning and adjustments are initiated. d. Major issues —include the decisions to be made when planning to apply the technique, and the limitations of the technique. This section also describes the caveats that must be considered prior to applying the Quality Control technique under discussion. e. Measurement and evaluation criteria —include both the criteria for evaluating the project as well as the effectiveness of the Quality Control technique itself in terms of benefits gained and cost incurred. f. Activities (implied by the technique)—in general, this section describes the planning that is necessary, the steps involved in the execution of the technique, and a description of the potential actions that can occur as a result of the application of the Quality Control technique. g. Related techniques —Quality Control techniques are not all independent of one another. Some may be redundant, and redundancy may not be entirely bad. For highly critical systems, a large degree of redundant checking may be appropriate. Other techniques may be complementary; that is, one enhances the other. Finally, certain techniques may be incompatible with one another. h. Bibliography —references to reading to supplement each brief description in this volume. SECTION 2 CAUSE AND EFFECT ANALYSIS Many of the software development and test processes rely on defect detection and correction through inspections, walk-throughs, reviews, and testing to achieve quality. However, reliance on detective techniques can be costly. Ultimately, one wants to use techniques that prevent defects from being introduced. The fewer defects that are created, the less rework is necessary and the less resources must be provided for the correction process.
- Johnson Edosomwan(Author)
- 1995(Publication Date)
- CRC Press(Publisher)
Chapter 5 Productivity and Quality Improvement Through Statistical Process Control This chapter presents the concepts and techniques of statistical process control (SPC) and its usefulness in improving productivity and quality in the business environment. A step-by-step methodology for implementing SPC and the design of the experiment are presented. A case study that shows the application of the SPC technique in a group technology production environment is presented. A procedure for designing an experiment is also offered. Statistical tools for data analysis are described. 5.1 PROCESS CONTROL DEFINITION Process control is a state whereby statistical inference techniques are used to m onitor and control a specified process in order to achieve improved quality and gains in productivity. The control concept utilizes both historical and present technical knowledge of the process in understand ing cause-and-effect relationships combined with statistical techniques to control and minimize defects. The implementation of process control concepts and techniques is achieved by providing a control system for defect and error detection, a control system for defect and error analysis, and a control system for defect and error correction. 139 140 5 Statistical Process Control 5.2 A PROCESS CONTROL SYSTEM DEFINITION A process control system is a feedback m echanism that provides inform a tion about the process characteristics and variables, process performance, action on the process inputs, transformation process, and action on the output The major components o f a process control system are presented in Figure 5.1. Figure 5.1 Components of a process control system. 5.3 Requirements of Process Management 141 5.3 THE KEY REQUIREMENTS OF PROCESS MANAGEMENT In order to improve the quality of products or services from a process,the following basic requirements are necessary.
eBook - PDF- J. D. Booker, M. Raines, K. G. Swift(Authors)
- 2001(Publication Date)
- Butterworth-Heinemann(Publisher)
1 Introduction to quality and reliability engineering 1.1 Statement of the problem In order to improve business performance, manufacturing companies need to reduce the levels of non-conformance and attendant failure costs stemming from poor product design and development. Failure costs generally make up the largest cost category in a manufacturing business and include those attributable to rework, scrap, warranty claims, product recall and product liability claims. This represents lost pro®t to a business and, as a result, it is the area in which the greatest improve-ment in competitiveness can be made (Russell and Taylor, 1995). The eect of failure cost or `quality loss' on the pro®tability of a product develop-ment project is shown in Figure 1.1. High levels of failure cost would produce a loss on sales and would probably mean that the project fails to recover its initial level of investment. In an attempt to combat high quality costs and improve product quality in general, companies usually opt for some kind of quality assurance registration, such as with BS EN ISO 9000. Quality assurance registration does not necessarily ensure product quality, but gives guidance on the implementation of the systems needed to trace and control quality problems, both within a business and with its suppliers. The adoption of quality standards is only the ®rst step in the realization of quality products and also has an ambiguous contribution to the overall reduction in failure costs. A more proactive response by many businesses has been to implement and support long-term product design and development strategies focusing on the engineering of the product. It has been realized for many years that waiting until the product is at the end of the production line to measure its quality is not good business practice (Crosby, 1969). This has led to an increased focus on the integration of quality into the early design stages of product development (Evbuomwan et al ., 1996; Sanchez, 1993).
- Harrison M. Wadsworth, Kenneth S. Stephens, A. Blanton Godfrey(Authors)
- 2004(Publication Date)
- Wiley(Publisher)
When a proper attitude has been commu- nicated throughout the organization and quality planning is being accomplished, consid- eration of the latter two categories (quality improvement and Quality Control) at the process level will achieve positive results. These two aspects of Quality Control are closely related and complementary. There is no rule concerning which should be applied first. This will vary with the process, prod- uct, or service. Applying these procedures to achieve control of quality may reveal places where improvement is needed and possible. Similarly, application of techniques to im- prove quality will often indicate where procedures are necessary. 11-2.1 Some Proven Steps in Quality Investigations Six simple steps have proven useful in studies of manufacturing and service processes [Stephens (1965a, 1965b)]. A prerequisite for success in applying these steps is to develop a quality consciousness concerning product variation and defect prevention. Another re- quirement is management awareness of their responsibility for quality improvement. For 344 Chapter 11. Process Control and Improvement Techniques each step there are related techniques, some as simple as recording and summarizing data, others involving control charts, and a few beyond the scope of this text. 1. Determine the magnitude of nonconformities, customer complaints, warranty claims, or other measures of undesirable process conditions. These may include off- target centering or variability too excessive for customer satisfaction. Useful measures of these characteristics may be attribute data. Variables data on important quality characteristics showing central tendency and variability are also im- portant. Another effective measure is cost. Experience has shown that many applica- tions of SPC have begun with a critical study of troublesome characteristics of a finished product or service.
eBook - PDF- Adedeji B. Badiru, Tina Agustiady(Authors)
- 2012(Publication Date)
- CRC Press(Publisher)
211 6 Project Quality Control When.Einstein.was.active.as.a.professor,.one.of.his.students.came.to.him. and.said:.“The.questions.of.this.year’s.exam.are.the.same.as.last.year’s!”. “True,”.Einstein.said,.“but.this.year.all.the.answers.are.different .” From collection of Albert Einstein’s quotes Quality.control.ensures.that.the.performance.of.a.project.conforms.to.speci-fications.and.meets.the.requirements.and.expectations.of.the.project.stake-holders.and.participants . .As.the.quote.from.Einstein.suggests,.expectations. can.be.designed.to.act.as.a.form.of.control . .The.objective.of.quality.control. is.to.minimize.deviation.from.project.plans . . Quality. control. must. be. per-formed.throughout.the.life.cycle.of.a.project—not.by.a.single.final.inspection. of.the.product . Quality Management: Step-By-Step Implementation The. quality. management. component. of. the. project. management. body. of. knowledge.consists.of.the.elements.shown.in.Figure 6 .1. .The.three.elements. in. the. block. diagram. are. carried. out. across. the. process. groups. presented. earlier.in.this.book . .The.overlay.of.the.elements.and.the.process.groups.are. shown.in.Table 6 .1. .Thus,.under.the.knowledge.area.of.quality.management,. the.required.steps.are: Step.1:. Perform.Quality.Planning Step.2:. Perform.Quality.Assurance Step.3:. Perform.Quality.Control Tables 6.2 .through.6 .4 .present.the.inputs,.tools,.techniques,.and.outputs.of. the.steps . .Improvement.programs.have.the.propensity.to.drift.into.anecdotal,. qualitative,.and.subjective.processes . .Having.a.quantifiable.and.measurable. approach.helps.overcome.this.deficiency . .Figure 6 .2 .shows.how.operational. efficiency.transitions.to.effectiveness,.quality,.and.then.productivity . 212 Statistical Techniques for Project Control Six Sigma and Quality Management The. Six. Sigma. approach. originally. introduced. by. Motorola’s. Government. Electronics. Group. caught. on. quickly.
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