An inspection is, most generally, an organized examination or formal evaluation exercise. In engineering activities inspection involves the measurements, tests, and gauges applied to certain characteristics in regard to an object or activity. The results are usually compared to specified requirements and standards for determining whether the item or activity is in line with these targets, often with a Standard Inspection Procedure in place to ensure consistent checking. Inspections are usually non-destructive.

Inspections may be a visual inspection or involve sensing technologies such as ultrasonic testing, accomplished with a direct physical presence or remotely such as a remote visual inspection, and manually or automatically such as an automated optical inspection. Non-contact optical measurement and photogrammetry have become common NDT methods for inspection of manufactured components and design optimisation.

A 2007 Scottish Government review of scrutiny of public services (the Crerar Review) defined inspection of public services as "... periodic, targeted scrutiny of specific services, to check whether they are meeting national and local performance standards, legislative and professional requirements, and the needs of service users."

A surprise inspection tends to have different results than an announced inspection. Leaders wanting to know how others in their organization perform can drop in without warning, to see directly what happens. If an inspection is made known in advance, it can give people a chance to cover up or to fix mistakes, which could lead to distorted and inaccurate findings. A surprise inspection, therefore, gives inspectors a better picture of the typical state of the inspected object or process than an announced inspection. It also enhances external confidence in the inspection process.