## 2 Theoretical Background
### Network Coordination in Omni-Channels  
Distribution systems are undergoing a transformation. Classic solutions in which channels are dedicated to specific customer segments are being displaced by multi-channel and omni-channel systems. This is influenced by a number of factors; supply-side factors include the digitalisation of supply chains, technological developments, and a change in the way companies think about return logistics, while demand-side factors [46] include an increased interest in e-commerce systems, widespread access to and ability to use various technologies, and changing customer behaviour patterns as a consequence of the COVID-19 pandemic (e.g., fear of crowds) as well as new shopping habits developed by the public during the pandemic (e.g., online shopping, use of parcel machines, and others) [47]. The development of e-commerce systems has been noticeable for many years; however, the pandemic period has made this form of sales even more dynamic. It can therefore be concluded that it is not the shopping trends themselves and the way in which e-commerce systems are organised, which are not new, but their dynamic development over the last five years that is transforming distribution systems and the market for logistics services. The complexity of modern distribution systems results from combining different distribution channels to serve the same customer. The network thus created, made up of many different channels between which product, information, risk, and finance are moved, is referred to as a multi-channel system [48]. In such systems, it is the customer who decides how he or she wants to purchase the product given the various purchase options available [49]. The multi-channel strategy has been discussed by both theorists and practitioners for many years. Some authors [50] also studied sales effectiveness in companies, with a focus on the use of different communication channels such as customer visits, telephone calls, and letters, as well as the then developing sales channels such as customer service centres and e-commerce. The paper indicated that the use of an omni-channel strategy could bring benefits in the form of greater sales efficiency, improved customer satisfaction, and increased market share. Since then, a multi-channel strategy has become a popular approach in the field of marketing, which is also reflected in numerous academic studies. Omni-channel distribution involves purchasing through indirect and direct marketing channels including websites, apps, retail shops, mail order catalogues, direct mail, email, etc. [51]. A characteristic feature of these types of channels is their independence. Each channel has its own prices, resources, and possibility to contact and interact with the customer [52]. The aim of the multi-channel idea is to reach the widest possible audience with the help of the media in which each group happens to be. As a result, an online shop can use Facebook, Instagram, a website, sponsored blog posts, and many others, for which a strategy can be developed separately. Consequently, the messaging and standard of service in the different venues may differ. Although the company appears in many places, it does not exploit the potential of building a relationship with its audience and getting them used to its presence. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{3}{*}{**Research Papers**} & \multicolumn{4}{c}{**Network Coordination or Network Governance Aspects**} \\ \cline{2-5}  & \begin{tabular}{c} **Important Role of** \\ **Logistics in the** \\ **Network Coordination** \\ \end{tabular}  & \begin{tabular}{c} **Logistics Coordination** \\ **Concept** \\ \end{tabular}  & \ \begin{tabular}{c} **Important Role of** \\ **Logistics Outsourcing** \\ **(Like 3 PL or LSP)** \\ \end{tabular}  & \begin{tabular}{c} **Network Coordination** \\ **in the Context of** \\ **Omni-Channels** \\ \end{tabular}