Sometimes a project affects multiple parties and teams that normally work separately. What this means is that different ways of working meet. Obviously there is a lot involved in this, in setting up the initial expectations, the various documentation and, ultimately on how all this is tested.
Considerable time can be lost if a central location for documentation and information is not set up at the beginning. As an example, an e-commerce platform would like to load track & trace information into a page they are building. That is, the information must be retrieved from an external party and then displayed on the internal page. To get started on this, it is best to ask and, of course, answer as many questions as possible beforehand.
Just what info is available? Which ones do we want to show and where on the page? What is under the control of the internal party, the external party or both? How and what can be tested, and who will do it all? If you as a tester have to figure all this out after development, a lot of time can be lost. Therefore: keep this info centralized in a place available to all parties involved. In addition, make sure everyone’s expectations are the same.
The importance of this is sometimes underestimated. The above example suffered greatly from poor communication, ambiguities about what was being delivered and the division of labor. As a result, after the go live, it became clear that a lot of things were not working as expected and needed to be fixed. Things that could easily have been prevented. So sometimes testing has to do not only with functionality, but equally with thinking about the completeness of information and communication.
Therefore, it has every advantage to involve a QA in initial refinements and other introductory meetings. Quality at the beginning, helps quality at the end as well as the time needed for development. In addition to your functionalities, test your lines of communication and documentation already.