ANOVA Gauge Repeatability and Reproducibility (ANOVA Gauge R&R) is a technique of Measurement Systems Analysis.  It evaluates the measurement system using the ANOVA (Analysis of Variance) Random Effects model.  This evaluation is not only limited to gauges, but also applicable to measurement systems like test methods, measuring instruments, and others.

ANOVA Gauge R&R determines the viability of a measurement system by measuring the amount of variability in the measurements, and comparing it with the total variability.  A measurement system may be affected by several factors like:

• Measuring instruments -  the gauge or the instrument, and all supports, mounting blocks, load cells, fixtures, etc.  Examples of variation sources are sloppiness in mating parts, ‘zero’ blocks, machine’s ease of use, etc.  Sources of variation in systems making electrical measurements include analog-to-digital converter resolution and electrical noise.
• Operators -  Efficiency of the people to carry out the verbal/written instructions.
• Test methods -  include how the devices are set up, parts are fixed, data is recorded, etc.
• Specification -  based on which the measurement is being reported.  Though engineering tolerance does not affect measurement, it is vital in the evaluation of the measurement system’s viability.
• Parts -  what are being measured.  While a measurement system may hold good for measuring steel block length, it may not be suitable for measuring rubber pieces.

Gauge R&R consists of the following two important aspects:

• Repeatability -  The variation in measurements taken on the same item, under the same conditions, by a single person or instrument
• Reproducibility -  The variability induced when different operators (or laboratories) measure the same item

Gauge R&R is used only for the precision aspect of a measurement system.  It is an important Six Sigma methodology tool, and is also a PPAP (Production Part Approval Process) documentation requirement.  GRR (Gauge R&R) measures parts under the established measurement system, and aims to report all possible variation sources in measurement, for understanding and assessment.

Multiple operators are needed for getting report on reproducibility errors.  The ASTM E691 Standard Practice requires at least 10 operators or laboratories.  Others demand only 2 or 3 for measuring the same parts.  For accounting repeatability errors, one operator measures the same part several times.  In case of multiple testing of different parts, full set of operations should be included in each measurement cycle.  For accounting operator interaction with different parts, usually five to ten parts are measured.  The GRR matrix enables the Quality Engineer to assess risks based on the vitality of the measurement and its cost.  There are several methods for determining the degree of replication and sample sizes.  The ‘10x2x2’ (ten parts, two operators, two repetitions) is a common sampling for some studies.

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ERP vendors are providing built-in configuration tools to enable to customers to change the working of the out-of-the-box core system.  The basic differences between configuration and customization are:

• Configuration like organizational trees, cost/profit center structure setups, purchase approval rules, etc. is required to some extent before making the software work.  But customization always remains an option.
• Configuration is open up to all the customers, whereas customization varies for each individual customer in the level of efforts to capture market.
• The changes to configuration are entered as data in vendor-supplied data tables, whereas changes in customization require some programming and/or table structure changes.
• The effect of configuration changes are predictable, whereas the effect of customization is unpredictable, requiring the implementation team to spend considerable time on stress testing.
• Configuration changes can be easily upgraded to new software versions.  Though some customizations pass through upgrades, they require re-testing.  And if the customizations are more extensive, then the upgrades would overwrite them and they need manual re-implementation.

While customizing ERP packages can be quite cumbersome and expensive, they also provide opportunity for achieving excellence in specific areas of business process.

ERP packages are also suitable for ‘extensions’, i.e., they can be combined with third-party programs which perform reporting, archiving, and republishing, and also for transactional data captures (like tills, scanners, and RFIDs).  But ERP applications have a set of rules to control the creation or changing of data.

ERP system helps in effective interfaces of tasks which include:

• Connection of required software for accurate forecasting
• Integration of functional areas ensuring productivity, efficiency, and effective communication
• Design engineering
• Order tracking, right from acceptance till fulfillment
• Revenue cycle, right from invoice till cash receipt
• Management of inter-dependent complex processes
• Tracking of the triangular process of purchase orders, inventory receipts, and costing
• Tracking accounting tasks at a granular level

continue reading Enterprise Resource Planning (ERP) – part 5

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