QA, QC & Testing

Understanding Testing

Testing allows products to be checked against the requirements specified to ensure that the product meets those requirements.

If during the testing of a product, it's revealed that the product doesn't meet the requirements set, then the product has not only failed the test but failed to meet the requirements.

If the testing of the product meets the requirements then the product has passed the test. Failure to meet the requirements could lead to the product not being fit for its intended market.

One of the aspects of testing is checking to see if the requirements have been achieved.

Consider the following:

A screw manufacturer develops different types of screws for the hardware industry. One of their best sellers is a 45mm screw which is popular with the building industry. The screw is designed to ensure adequate penetration of brick walls without damaging the brick strength.

The length of 45mm is part of the requirements for developing these screws. As even the slightest change in the length of the screw could cause damage to the brick work. During the production of these screws, the final checks involve testing the screw to ensure that it is of the correct length as per the requirements.

This is done by running a special laser light over the screw which is used to calculate the length. Any screws that are not 45mm fail this test and are scrapped. Those that are exactly 45mm pass this test and are packaged for delivery to the many hardware stores that sell this screw.

The above example highlights the importance of testing the requirement of a 45mm length. As any screws failing this requirement could cause damage not only to the brickwork but the screw manufacturer's image.

More Than Just Requirements

Whilst the main aim of testing is to ensure that the requirements specified have been met. Testing can give much more than this.

Consider again a screw manufacturer and their brand of 45mm screws, the requirements state that the screws are made of steel and are exactly 45mm long. Adhering to both these requirements in theory, leads to screws that are ready for sale.

Testing can take this a step further by ensuring that the screws are of the quality expected. The last thing the screw manufacturer wants to do is sell screws that fail whilst being used.

They could be part of a batch made with poor quality steel or a batch where the hardening process hasn't been used effectively enough. There's nothing worse for the screw manufacturer to end up being sued by their customers for substandard screws.

Testing can help increase the quality of products produced, reducing the chances of being sued for product failure later on.

As well as checking requirements, testing can be used to check the quality of a product.

It's important to realise that as humans there is a susceptibility to make mistakes at one point or another. Even the brightest, bravest and boldest amongst us can still succumb to making a mistake or two.

Throw in some external pressures such as time constraints, budget headaches, limited resources and the ugliest of them all, politics, the chances that mistakes will occur will dramatically increase.

Testing can help in isolating these mistakes and revealing them well before any real damage occurs. So if there's an error made during ordering and the wrong quality steel is ordered, testing can be used to alert the organisation that the quality of steel used is suspect. Allowing the screw manufacturer to stop these screws from being sold to their customers.