Acceptance criteria are the conditions that a software product must meet to be accepted by a user, a customer, or other system. They are unique for each user story and define the feature behavior from the end-user’s perspective.
Success of any project depends on the ability of a development team to meet their client’s needs. The communication between the client and the development team plays a vital role in delivering a solution that fits product and market requirements. The issues arise if customers explain their needs too vaguely and the team can’t understand clear requirements and eventually the business problem behind them.
There are many types of criteria’s such as Contamination (foreign debris encapsulated within the parts), Flash (Excess material forced into split/parting lines etc.), Flow lines/ weld lines/ knit lines (Cold flow resulting in a poor join between two material flow fronts), Gate bloom (Pale discoloration around gate area), Jetting / crazing (irregular flow path commonly found around the gate area), Gas burn (caused by localized temperature increase of trapped gases), Color dispersion (irregular color), Scratches/knite lines, Voids & Sinkage /sink marks (Collapse in surface area).
To perform during homologation and in production according to the frequency defined in the specification, furthermore, a method of analysis and testing criteria can be specified such as: Leakage test (Seal in the vacuum chamber “simulant & colored water”), Drop test on plastic bottles & jars (Resistance to falling- PE), Control of the distribution of material (min. thickness of plastic bottles), Control of ovalization (Ovalization “qualitative”), Control of weight & full volume, Axial resistance of the bottle, Surface deformation, Stress cracking control test for thermo- plastic materials except pvc, pmma & styrenes (sensitivity of stress cracking), Dimensional inspection of bottles & jars, (Verticality/ Coaxiality, Stability), Appearance inspection (Appearance: major defect, no flashes on the bottom weld line, critical defect, minor defect, AC Zero defect), Accelerated ageing under light (Ageing in light- window).
These criteria’s specialized for Copar, but mainly there are several criteria’s for each company, and they depends on several ranges of measuring and testing to decide whether the sample is accepted or not accepted.
Moreover, the difference between requirements & acceptance criteria is that requirements are at a higher level while acceptance criteria at a lower level, more towards the delivery point. … Requirements are what you are supposed to do. Acceptance criteria are agreed upon measures to call a project “done”, they are a set of statements, each with a clear pass/fail result.
Regarding who should write it, generally, they are initiated by the product owner or stakeholder. They are written prior to any development of the feature. Their role is to provide guidelines for a business or user-centered perspective.