The phrase "rolling basis" means that something is ongoing and continuously happening, without a fixed start or end date. It suggests that things are being done or decided progressively, one after another, as time goes on. Full definition
This sugar cookie mix is very moist, so I actually rolled the bases for my individual fruit pizzas on the actual cookie sheet. (miglutenfreegal.com)
On top of the trust, offer protection on a basket of 100 single - A names on a five year rolling basis. (alephblog.com)
Developed roll based applications that allowed administrator inventory management capabilities, draft / edit various categories and cards, fonts and card layouts and other attributes. (resumemycareer.com)