The telecommunication industry is currently adapting to the changes in market dynamics brought about by the new services and features, introduced with the transition from 4G to 5G and under discussion as the industry moves to the forthcoming 6G. The underlying industry challenges are to understand the new business opportunities created by the virtualisation of information and communication technologies (ICT) and to ensure companies are best placed to maximise their delivery of value to the 5G and Beyond 5G (B5G) markets. Although early in the development cycle, it is expected that similar issues will arise with the future deployment of 6G networks, and so it is important for the economic viability of those networks to consider value creation in parallel with the on-going technology development. The 6G Industry Association (6G-IA) sub-working group Business Validation, Models, and Ecosystems (BVME-SG) has reacted to these challenges by previously publishing the white paper 5G and Beyond 5G Ecosystem Business Modelling. This new white paper builds on and extends that prior work, by presenting a focused application of the business modelling framework. To guide the discussion, the Industry 4.0 (I4.0) vertical is taken as an exemplary implementation that can be easily adapted and reproduced by other verticals. The proposed framework consists of five steps that are intended to support stakeholders in the 5G/B5G ecosystem to explore business opportunities and understand how variations in ecosystem configurations can affect their operations. The result of the implementation of those steps shows that the framework is capable of uncovering key insights affecting many strategic questions arising from the changes in ecosystem dynamics. The white paper also considers how the analysis extends to 6G, providing insights that will be useful when exploring business opportunities that arise as 6G technology develops in the near future.This white paper also explores the question of cost resulting from ecosystem variations, first at a high level of abstraction (e.g., to identify opportunities to create synergies, competitive tensions and economies of scale), second using more detailed approaches to assess the technoeconomic sustainability of the forthcoming 6G ecosystem, a major factor affecting investment decisions and company strategy. That is achieved by re-defining how studies are performed to capture the technoeconomic viability of 5G/B5G ecosystems, i.e., it is proposed to perform the analysis: 1) on a per network deployment basis, for a given scale and set of dimensioning assumptions, and 2) mapped on ecosystem roles towards assessing viability on a per actor/role basis. The final section of the white paper looks toward the implications expected from the transition from 5G to 6G in terms of additional ecosystem actor roles. The emergence of these new roles is likely to be driven by the end-to-end (E2E) architecture of the 6G networks in terms of being even more distributed and disaggregated compared to current 5G solutions. However, due to the fact that both network generations will be built on distributed and disaggregated design principles, it is expected that the framework presented in this white paper will be equally applicable as the industry moves from 5G to the 6G era.