Regarding the current wide range of complexities, topologies and main characteristics linked to network environments, a large variety of collaborative network configurations can be studied and analysed. Due to the emerging importance for researchers, academia as well as practicioners, this paper focuses on collaborative and non-hierarchical networks. This type of networks are normally characterised by managing the decision-making process in a distributed manner. Hence, the exchange of information and the establishment of collaborative processes and commitments are core activities for the network partners. For this, the main orientation of this paper is, through applying the literature review method, to cover the relevant collaborative processes that SMEs need to consider when they participate in non-hierarchical networks. From the results of the literature reviewed it is determined that under the non-hierarchical network perspective, SMEs may find various difficulties to adopt collaborative processes within an optimal performance. A relevant process is the one related with the operation planning, in which this paper focuses on its collaborative perspective. In this context, and regarding the amount of agreements and standardised processes required, supporting the collaborative operational planning to produce efficient and acceptable solutions for SMEs might become one of the most complex activities to participate in collaborative non-hierarchical networks. The objective of this paper is to address the main barriers regarded the operational planning processes in non-hierarchical networks under a collaborative perspective. Moreover, a conceptual solution based on multi-agent systems is addressed, in which its application to non-hierarchical networks is analysed in order to deal with the operational planning process in collaborative and distributed environments.