qm-statistical quality control

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    Statistical Quality Control Basic Concepts

    Product Control Process Control

    Variations in Quality

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    Basic Concepts When small samples are taken

    continuously on a regular basis,

    and the data analysedstatistically, valuable informationcan be derived.

    Control charts forms an integralpart of production process.

    Provides timely warning signal &

    for corrective action.

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    Basic Concepts The effectiveness of control

    charts depends on how promptly,

    the warning is understood andheeded and necessary actiontaken to correct the process.

    Helps manufacturer in identifyingand eliminating causes fordefectives or failures in repetitiveproduction processes.

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    Statistical Process Control SPC is the primary analysis tool of

    quality improvement.

    It is the applied science that helps youcollect, organize and interpret thewide variety of information availableto your business.

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    Statistical Process Control

    - Aim To Achieve Defect Prevention. To Pursue Never-ending Improvement. To Reduce Variability, Delivery Times,

    Completion Times, Methods, Attitudes,Equipment and Material.

    To Produce Components Consistently

    within Specifications. to give us Statistical Signal whenSpecial causes of Variation arePresent.

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    Process Control Tools Flow chart to understand what is being

    done. Check sheets & tally charts to observe

    the frequency of occurrence of theprocess.

    Graphs to see the pictorial

    representation of the numbers. Cause and effect analysis to study thecauses of the problems.

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    Process Control Tools Pareto analysis to segregate serious

    problems from the minor once. Scatter diagrams to study the

    relationship between variousinteracting factors.

    Control charts to interpret and decide

    which variations to control and goabout. Histograms to appreciate as to how

    the variations in frequency of

    occurrence appear.

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    Process Control -

    Advantages Greater consistency in fulfilling

    customer's requirements leads to

    greater customer satisfaction. Reduced variation in internal

    processes leads to less time and

    money spent on rework andwaste.

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    Product Control Product Control helps to ensure that

    the firm follows the proper regulatoryand financial procedures with regardto the firm's business transactions,especially as they relate to issues ofcustomer protection and the liquidity

    ratio of the firm. It must also reconcile the securities,commodities, futures and fixed incomesettlements, and monitor the financialand regulatory exposures associated

    with them, to further ensure the

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    Product Control Reconciliation of P&L to traders

    estimates and attribution.

    Control analysis - posting to theledger, accuracy of P&L.

    Balance sheet analysis.

    Internal management reporting.

    Price verification of all products.

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    Variations in Quality Common cause of variation account

    for 80 90 percent of the observedvariation in a production unit.

    The remaining 10 20 percent resultsfrom special case of variation, oftencalled assignable causes.

    Special causes include bad batch ofmaterial purchased, poorly trainedoperator, excessive tool wear,miscalibration of measuring

    instrument etc.

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    Variations in Quality Common cause of variation account

    for 80 90 percent of the observedvariation in a production unit.

    The remaining 10 20 percent resultsfrom special case of variation, oftencalled assignable causes.

    Special causes include bad batch ofmaterial purchased, poorly trainedoperator, excessive tool wear,miscalibration of measuring

    instrument etc.

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    Variations in Quality Way to reduce the variation due to

    common causes is to change thetechnology of the process themachines, materials, methods, ormeasuring systems.

    Variation due to special cause can be

    identified through the use of charts. Special cause of variations areidentified by the production operatorsand their immediate super visors

    through charts and make the