The A+S Programme includes several working groups that meet regularly to discuss topics such as greening initiatives in general, the sustainable procurement of timber, construction and responsible procurement in general. Occasionally, other special groups are set up to deal with issues such as the greening of events or the innovation in contracting methods.

Regarding the relationship with other external agents, Barcelona City Council is an active participant in the ICLEI's Procura+ Campaign (Barcelona held the vice-presidency of the campaign until 2012), of the Sustainable Public Procurement Program of the United Nations and the C40 and Eurocities international networks, as well as in the Big Buyers Initiative, an exchange group of European administrations promoted by the European Commission and coordinated by ICLEI and Eurocities.