Controlling changes

Why changes need control

Change is normal. Requirements evolve during a project, components become obsolete, and designs are improved. The risk lies in changes made informally: a substituted component that changes temperature rise, a revised drawing that one party never received, a setting adjusted on site and never recorded. Invitrona handles change as a controlled step with a record.

Sources of change

• Customer change: a revised load, a new specification clause, a different installation location
• Invitrona change: a design improvement, a component substitution or a process change
• Change found on site: a condition that differs from the requirement record

How a change is assessed

Every material change is recorded with:

• What is changing and why
• The requirement, configuration or document affected
• The technical effect, including any effect on ratings, protection or verification
• The effect on cost, programme and documents
• Who approves it, and the revision at which it takes effect

The assessment is proportionate. A correction to a label template does not need the same review as a change of semiconductor device, but both are recorded.

Changes during a project

When a customer change arrives after order, its effect on the configuration, price and programme is stated before work proceeds. Verbal agreements are confirmed in the controlled order record. The proposal and drawings are re-issued at a new revision, and superseded versions are withdrawn.

Changes in OEM production

For OEM programmes, changes that could affect form, fit, function, reliability or approvals of the supplied part are notified to the customer before they reach production. The customer may need to re-validate the product, so notification comes early enough for that to be planned. The approved configuration does not change silently between batches.

Changes on site

Settings changed during commissioning or service are recorded in the commissioning or service report with their reason. A configuration that has been altered in the field is identified as such in the unit's record.

Small changes are still changes

Some changes look minor: a different cable gland, an alternative fan, a revised label. They are still assessed, because a small change can affect temperature rise, ingress protection or the documents a customer has approved. The assessment may conclude quickly that there is no effect on the agreed requirement, but the conclusion is recorded with the revision.

Questions you can ask

• How will I be notified of a change that affects my order or product?
• Which revision of the configuration is my order built to?
• How are changes made on site during commissioning or service recorded?

What this means for a buyer

You know which revision of a document or configuration applies, and you are asked before a change affects what you agreed. The history of changes stays with the order and the unit.