Elements and Performance Criteria

Sampling scheme may include:

sampling for attributes or sampling for variables

batch, continuous or custom made products

number of items/samples

size of sample

timing of sampling

location of sampling points

type of sample

number/type of measurements to be done on each sample

sampling equipment

measurement/testing equipment/methods


Procedures includes all work instructions, standard operating procedures, formulas/ recipes, batch sheets, temporary instructions and similar instructions provided for the smooth running of the plant. They may be written, verbal, computer based or in some other form.

For the purposes of this Training Package, ' procedures' also includes good operating practice as may be defined by industry codes of practice (eg Good Manufacturing Practice (GMP), Responsible Care) and government regulations.


Handle data may include:

calculating means, ranges, mean of means, standard deviation (using appropriate calculation aids)

entering data into a software package

recording data either in writing or electronically

other required manipulations of the data.


Control charts may include:

run

tally

mean/range

attributes

other relevant charts


Random variation is the term used in statistical control to refer to those variations for which no cause can be found.


Non-random, also called identifiable cause, or assignable cause or special cause are those variations for which a cause can be found and so the cause of the variation eliminated. Non-random variation may also be used to predict possible breaches of the control limits.


Control limits, also referred to as process capability are those limits within which the process will operate if it is 'under control'.


Cost of non-conformance includes:

reprocessing/rework

expediting

unplanned service

excess inventory

complaint handline

downtime

returns

scrap

labour costs

material costs

infrastructure costs/overhead

utility costs


Appropriate limits may include:

1 sigma warning limits

2 sigma warning limits

3 sigma control limits

6 sigma limits

Overview of assessment requirements
The competent person will be able to apply statistical theory to a process to interpret and reduce its variation.

What critical aspects of evidence is required to demonstrate competency in this unit?
Evidence of the application of statistical theory to a process should be available

In what context should assessment occur?
Assessment will need to occur in an organisation implementing statistical process control or by project.

Are there any other units which could or should be assessed with this unit or which relate directly to this unit?
This unit could be assessed concurrently with other units dealing with process capability and/or change management.

What method of assessment should apply?
Assessors must be satisfied that the person can consistently perform the unit as a whole, as defined by the elements, performance criteria, skills and knowledge. A holistic approach should be taken to the assessment.
Assessors should gather sufficient, fair, valid, reliable, authentic and current evidence from a range of sources. Sources of evidence may include direct observation, reports from supervisors, peers and colleagues, project work, samples, organisation records and questioning. Assessment should not require language, literacy or numeracy skills beyond those required for the unit.
The assessee will have access to all techniques, procedures, information, resources and aids which would normally be available in the workplace.
The method of assessment should be discussed and agreed with the assessee prior to the commencement of

What evidence is required for demonstration of consistent performance?
Generally the application of statistics over a period of time would be required to generate sufficient evidence

What are the specific resource requirements for this unit?
Access to an organisation using statistical control.