# Collaborative Networks: A Pillar of Digital Transformation
## 7 Discussion of New Research Challenges  
Past initiatives in CN research and industrial development led to a large portfolio of theoretical models, mechanisms, and empirical knowledge, which can provide good contribution to the identified collaboration requirements of the ongoing industrial revolution, as summarized above. Furthermore, the catalytic effect of Industry 4.0, acting as a melting pot for the convergence of multiple knowledge areas, and the digital transformation \"movement\", raise new research challenges, eventually leading to Collaborative Networks 4.0. These challenges are illustrated by the following list, which results from various inputs, namely (1) identified gaps in the literature and trends analysis, (2) acquired experience in various related research projects, and (3) a synthesis of ideas discussed in recent international conferences (e.g., the editions PRO-VE and DoCEIS of the last 3 years). The challenges identified are \begin{table}
\begin{tabular}{c p{284.5 pt}} \hline \hline
**Strategies** & **Description** \\ \hline \multirow{4}{*}{**Collaboration**} & Working together to better manage disruptions through exchanging data, resources, and ideas (collaborative problem solving) [118]. Examples: risk sharing, information sharing, trust building among partners, negotiation, plug and play teaming, and product lifecycle management. \\ \hline \multirow{2}{*}{**Fault Injection**} & A test-based approach for evaluating survivability of a system, by intentionally injecting faults to a system to ensure it can tolerate and recover from error conditions [120]. Examples: Simian Army, GameDay. \\ \hline \multirow{2}{*}{**Fail Fast**} & To quickly fail deliberately (when the impact is small) to learn from failures [121]. \\ \hline \multirow{2}{*}{**Feedback Mechanism**} & To maintain the system’s stability and prevent problems by comparing its status with reference values to know if it is necessary to make a modification [85]. \\ \hline \multirow{2}{*}{**Graceful Degradation**} & Allowing to work with limited functionality to prevent entire system’s downtime [85]. \\ \hline \multirow{8}{*}{**Network Structure Planning**} & Deciding on the structure, volume, location, and capacity of systems through different strategies such as [85]: \\ \cline{2-2}  & Fragmentation, which is related to decentralization and distribution. \\ \cline{2-2}  & Modularity, consisting of separate linked components to reduce complexity and change immediately. \\ \cline{2-2}  & Integration, a combination of subsystems, resources, processes, etc. to facilitate agility and flexibility. \\ \hline \multirow{2}{*}{**Optionality Creation**} & Having lots of options to experiment with uncertainty that gives freedom to respond to unforeseen circumstances and benefit from opportunities [116]. \\ \hline \multirow{2}{*}{**Real-time Monitoring**} & To observe, and optionally signal alarms on the state of the system for quicker responses to problems and even predictive maintenance [120]. \\ \hline \multirow{2}{*}{**Swarming**} & Increasing the resilience of a system by decentralized coordination and extending the concepts of self-organizing and self-synchronization by real-time information sharing [119]. \\ \hline \multirow{2}{*}{**Weak links**} & A lower level of connection between components in order to stop propagation failures [121]. \\ \hline \hline \end{tabular}
\end{table} 
Table 3: A sample of resilience/anti-fragility support strategies. not specific of any singular dimension of Industry 4.0; rather most of them cross various dimensions. As such, the adopted structure was to group them by thematic proximity. _(a) Extended scope_  
**Extend the CN perspective to complex CPS**  
_Context_: Previous works on CPS/IoT have been mostly focused on the core technological issues, e.g., interconnectivity, integration platforms, safe communications and protocols, control, and approaches to cope with limited energy, computing and communication capabilities.