"Ideation" and "concept development" are loose descriptors for the general process of generating and exchanging ideas as part of the marketing process. Ideation sessions are typically conducted among small groups, and can last from a few hours to a few days. The intensity, scope, and duration are dependent upon the category, decision-makers, and opportunity costs of the issue at hand.
Ideation sessions can be conducted at any stage of the product life cycle, from pure innovation and "blue sky" exercise, to product and service development, to refinement, and then production or delivery. Ideation is an essential part of any process in which end-user or influencer feedback is needed to begin to frame the delivery of a product or service.