ECHOES Integration Strategy for datasets, tools and workflows with potential for reuse in ECHOES (D3.1)

ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows European Cloud for Heritage Open Science Deliverable 3.1 – Integration Strategy for datasets, tools and workflows with potential for reuse in ECHOES HORIZON-CL2-2023-HERITAGE-ECCCH-01 Horizon Innovation action Responsible authors: Dimitris Kotzinos (CNRS - CY Cergy Paris University), Sally Chambers, Laure Barbot and Matej Ďurčo (DARIAH-EU), Gianni Dalla Torre (EGI Foundation) © 2025 by the authors, the ECHOES consortium. This work is licensed under a “CC BY 4.0” license. Project start 1 June 2024 Project duration 60 months Document Identifier 10.5281/zenodo.17751335 ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 2 Deliverable Information Project Number 101157364 Acronym ECHOES Full title European Cloud for Heritage OpEn Science Project URL https://www.echoes-eccch.eu/ EU Project Officer Christian WILK Change log Date Version Author Change 05/09/2025 V0.1 Sally Chambers, Matej Ďurčo, Laure Barbot (DARIAH-EU), Dimitris Kotzinos (CNRS-CYU), Gianni Dalla Torre (EGI Foundation) Outlines 13/09/2025 V0.2 Laure Barbot (DARIAH-EU) Writing resources section Deliverable 3.1 Title Integration Strategy for datasets, tools and workflows with potential for reuse in ECHOES Work Package 3 Title Enhancing Collaboration and Integration Submission date 10/12/2025 Pages 38 Keywords Digital Cultural Heritage; Integration Strategy; Integration Roadmap; Services; Data; Workflows, Cultural Heritage Cloud Lead Partner CNRS – CY Cergy Paris University Responsible Author Dimitris Kotzinos (CNRS-CYU) Authors (Partners) Sally Chambers, Laure Barbot and Matej Ďurčo (DARIAH-EU), Gianni Dalla Torre (EGI Foundation) Contributors Antoine Isaac (Europeana Foundation). Carlos Andujar (UPC), Joanna Kowalska (PCSS), Emmanuel Demetrescu (CNR) Kerstin Arnold (APEF), Xavier Rodier, Mailane Maira Messias Sampaio, Louise Gadoin (CNRS), Charlotte Gallini, Rémi Petitcol (FSP) ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 3 22-31/10/2025 V0.3 Sally Chambers, Laure Barbot (DARIAH-EU), Dimitris Kotzinos (CNRSCYU), Gianni dalla Torre (EGI Foundation), Carlos Andujar (UPC), Joanna Kowalska (PCSS) Writing levels of integration section 30/10/2025 V0.4 Joanna Kowalska (PCSS) Expanded section about Integration Levels 5/11/2025 V0.5 Sally Chambers (DARIAH-EU) Writing purpose and scope 7/11/2025 V0.6 Charlotte Gallini (FSP) Drafting ECHOES ecosystem section 12/11/2025 V0.7 Gianni Dalla Torre (EGI Foundation), Laure Barbot (DARIAH-EU) Writing Integration roles section 16/11/2025 V0.8 Sally Chambers, Matej Ďurčo, Laure Barbot (DARIAH-EU) Revisions to Purpose and Scope, Integration Principles and ECHOES ecosystem 26/11/2025 V0.9 Louise Gadoin (CNRS) Revisions of the ECHOES ecosystem section and feedback 26/11/2025 V0.10 Emanuel Demetrescu (CNR) Revisions of the integration principles 26/11/2025 V0.11 Laure Barbot, Sally Chambers (DARIAHEU), Matej Ďurčo (EGI Foundation) Integration of feedback 27/11/2025 1.0 Dimitris Kotzinos (CNRS-CYU), Antoine Isaac (Europeana) Internal Review 28/11/2025 1.1 Laure Barbot, Sally Chambers (DARIAHEU), Matej Ďurčo (EGI Foundation) Integration of feedback 03/12/2025 1.2 Dimitris Kotzinos (CNRS-CYU) Rewriting levels of integration section 04/12/2025 1.3 Antoine Isaac (Europeana) Internal Review 05/12/2025 1.4 Laure Barbot, Matej Ďurčo, Sally Chambers (DARIAH-EU), Dimitris Kotzinos (CNRS-CYU) Integration of feedback and Final Review 05/12/2025 1.5 Xavier Rodier (CNRS) Final Review ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 4 1. Abstract The aim of the ECHOES Integration Strategy (D3.1) is to facilitate the development of the Cultural Heritage Cloud as a shared platform offering access to data, advanced digital tools and state-of-theart workflows for the creation and analysis of a new generation of semantically rich and collectively produced heritage assets. The strategy helps to ensure that the Cultural Heritage Cloud becomes a coherent, sustainable and user-friendly infrastructure, optimising the reuse of the outcomes of EU and national cultural heritage projects, to meet the needs of the cultural heritage and research communities. The ultimate goal of this integration effort is to interconnect these datasets, tools and workflows in a federated manner, informed by the Community needs. With its roots in the Cultural Heritage Cloud Founding Principles 1 , the ECHOES Integration strategy defines three strategic pillars (section 6) as the goals to be achieved to fully realise the ECCCH as a collaborative and federated cloud. From these pillars, a series of integration guiding principles are extracted (section 7), which are used to determine integration priorities by considering community needs, technical readiness and governance dimensions. The pillars and the guiding principles will enable ECHOES to navigate the integration expectations of the diverse range of actors in the ECHOES ecosystem (section 8), by setting clear objectives to reach and orientate the choices to be made. The core of the Integration Strategy to build a Federated Digital Commons by connecting distinct nodes in a federated ecosystem is outlined in Section 9. This includes the vision of creating a Distributed Data Fabric where applications, services, data and workflows are dynamically federated, scaled and actioned or used. The ECHOES Governance Model is presented in section 10, with a specific focus on the role of the Stakeholders Council and of the ECHOES Integration Task Force (EITF) to enable ECHOES to make informed, collective, and transparent integration decisions. The ECHOES Integration Roadmap (D3.2), which operationalises the integration strategy, is also introduced. How the roadmap will be managed by a number of integration roles in a series of integration cycles is outlined. The need to continue integration activities once the Cultural Heritage Cloud becomes a sustainable longterm cultural heritage data infrastructure, in anticipated. Finally, the strategy concludes (section 11), by emphasising the pivotal role that the ECHOES Integration Strategy and Roadmap play in ensuring that the Cultural Heritage Cloud becomes a reality. Disclaimer: Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Executive Agency. Neither the European Union nor the granting authority can be held responsible for them. 1 Pollé, A., Vendrix, P., Czech, L., Petitcol, R., Gallini, C., Stadlinger, E., Steindl, C., Puhr, A., Marçal, E., Szatucsek, Z., Habibi Minelli, S., Nowak, A., EF, CNRS, FSP, ONB, PCSS/PSNC, & META. (2025). ECHOES Founding principles of the Cloud Governance (D10.1). Zenodo. https://doi.org/10.5281/zenodo.17599162 ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 5 2. Table of Contents 1. Abstract ............................................................................................................................................... 4 2. Table of Contents ............................................................................................................................... 5 3. List of figures and tables ................................................................................................................... 7 4. List of abbreviations .......................................................................................................................... 8 5. Purpose and scope ............................................................................................................................. 9 6. Strategic pillars ................................................................................................................................ 11 7. Guiding Principles for Integration ................................................................................................. 12 8. ECHOES ecosystem ........................................................................................................................... 14 Within ECHOES.............................................................................................................................................. 15 Vertical Applications ..................................................................................................................................... 15 ECHOES Cascading Grants .......................................................................................................................... 16 Within ECCCH ................................................................................................................................................ 16 Beyond ECCCH .............................................................................................................................................. 18 Broader European ecosystem ..................................................................................................................... 18 Data Space for Cultural Heritage ................................................................................................................ 19 European Open Science Cloud (EOSC) ....................................................................................................... 19 Joint Programming Initiative on Cultural Heritage (JPI CH) ..................................................................... 20 High Performance Computing and AI Factories ....................................................................................... 20 ESFRI Research Infrastructures and related initiatives ............................................................................ 21 National Initiatives across Europe .............................................................................................................. 21 9. ECCCH Integration Strategy: Building the Federated Digital Commons .................................. 23 Integration Units (IU) ................................................................................................................................... 23 Levels of integration .................................................................................................................................... 23 The Central Role of the Heritage Digital Twin (HDT) ................................................................................. 25 The HDT Creation Lifecycle .......................................................................................................................... 25 Provenance and Quality: The "Paradata" ................................................................................................... 25 Resource Integration Matrix ....................................................................................................................... 26 Data and Metadata Integration .................................................................................................................. 26 ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 6 Applications and Services Integration ........................................................................................................ 27 Workflows Integration ................................................................................................................................. 28 Integrating European and National initiatives, institutions and individuals .......................................... 29 The Final Federated (Integrated) Architecture .......................................................................................... 30 10. Integration Governance .............................................................................................................. 32 Stakeholders Council.................................................................................................................................... 32 ECHOES Integration Task Force .................................................................................................................. 33 Managing the roadmap ............................................................................................................................... 33 Integration roles ........................................................................................................................................... 34 Integration Cycles ........................................................................................................................................ 35 11. Conclusion ..................................................................................................................................... 36 References ............................................................................................................................................... 37 ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 7 3. List of figures and tables Figures: - Fig. 1 ECHOES Ecosystem - Fig. 2 ECHOES Governance Structure Tables: - Table 1: Digital Twin integration levels - Table 2: Data and Metadata Integration levels - Table 3: Applications and Services Integration levels - Table 4: Workflows Integration levels - Table 5: Community Integration Levels ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 8 4. List of abbreviations 3S Simple Storage Service AAI Authentication and Authorization Infrastructure API Application Programming Interface CH Cultural Heritage CLARIN Common Language Resources and Technology Infrastructure DARIAH Digital Research Infrastructure for the Arts and Humanities DT Digital Twin E-RIHS European Research Infrastructure for Heritage Science ECCCH European Collaborative Cloud for Cultural Heritage EITF ECHOES Integration Task Force EOSC European Open Science Cloud ERIC European Research Infrastructure Consortium ESFRI European Strategy Forum on Research Infrastructures FAIR Findable, Accessible, Interoperable, and Reusable GLAM Galleries, Libraries, Archives, and Museums GPU Graphics Processing Unit HDT Heritage Digital Twin HDTO Heritage Digital Twin Ontology HPC High Performance Computing JPI CH Joint Programming Initiative on Cultural Heritage KB Knowledge Base VA Vertical Application ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 9 5. Purpose and scope The ECHOES Integration Strategy plays a pivotal role in realising the Cultural Heritage Cloud. To enable this, ECHOES is establishing a shared platform offering access to data, advanced digital tools and state-of-the-art workflows for the creation and analysis of a new generation of semantically rich and collectively produced heritage assets. By bringing together diverse actors from various fields and disciplines from across the sector into a cohesive community of heritage professionals and researchers, it will enable collaborative scientific research. The Integration Strategy facilitates the creation of a coherent, sustainable and user-friendly infrastructure, optimising the reuse of the outcomes of EU and national cultural heritage projects, to meet the needs of the cultural heritage and research communities. It is informed by a comprehensive gap analysis, undertaken in close collaboration with the Communities pillar. This gap analysis combines the results of the ECHOES Consultation and the inventory of existing datasets, tools, and workflows with potential for reuse. The ultimate goal of this integration effort is to interconnect these datasets, tools and workflows in a federated manner, informed by the Community needs. An opensource infrastructure and modular architecture are key. With its roots in the Cultural Heritage Cloud Founding Principles 2 , the ECHOES Integration strategy defines three key pillars (section 6) as the goals to be achieved to fully realise the ECCCH as a collaborative and federated cloud. From these pillars, a series of integration guiding principles are extracted (section 7), which are used to determine integration priorities by considering community needs, technical readiness and governance dimensions. The pillars and the guiding principles will enable ECHOES to navigate the integration expectations of the diverse range of actors in the ECHOES ecosystem (section 8), by setting clear objectives to reach and orientate the choices to be made. ECHOES strategy to break down the complexity is to elaborate a resource-oriented approach of the integration activities, leading to the identification of Integration Units (section 9): it is not projects or initiatives per se that are integrated into the Cultural Heritage Cloud, but rather the resources - or assets, or key exploitable results – that their communities use or produce, and these resources interact with the Cultural Heritage Cloud Components. Once this is clarified, it is of outmost importance for the ECHOES Integration Strategy to set up as well an environment in which a variety of actors and resources can interact, and this is why different levels of integration (section 9) are also conceptualised: in order to provide a gradual and inclusive framework encompassing both the available capacities and resources of the teams willing to contribute to the collaborative cloud and, on the other side, targeting the realisation of a fully Federated Architecture. The different levels of integration are there to also provide a vision on how at the end of the day the Cultural Heritage Cloud could function as a platform for collaborative and 2 Pollé, A., Vendrix, P., Czech, L., Petitcol, R., Gallini, C., Stadlinger, E., Steindl, C., Puhr, A., Marçal, E., Szatucsek, Z., Habibi Minelli, S., Nowak, A., EF, CNRS, FSP, ONB, PCSS/PSNC, & META. (2025). ECHOES Founding principles of the Cloud Governance (D10.1). Zenodo. https://doi.org/10.5281/zenodo.17599162 ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 16 ECHOES Cascading Grants The ECHOES Cascading Grants Programme provides funding for consortia led by Cultural Heritage Institutions (CHIs) to engage with the Cultural Heritage Cloud 5 . The programme supports up to 50 projects across three calls to enhance digital engagement, data sharing, and collaboration. Smaller and medium-sized or lesser resourced CHIs are especially encouraged to apply. The Key focus areas of the three calls are: • Call 1: Data – Projects that contribute heritage data to the Cultural Heritage Cloud and would like to make use of its tools and infrastructure. • Call 2: Engagement and Collaboration – Initiatives that promote digital skills, awareness, and collaboration with CHIs. Projects that strategically enlist professional umbrella organisations to promote the benefits of the cloud at the sector level to the different CH communities would be particularly welcomed. • Call 3: Data and Vertical Applications – Projects that contribute new datasets to the Cultural Heritage Cloud or develop applications that integrate with enhance its functionalities. The outcomes of the projects funded under the ECHOES Cascading Grants Programme are a key potential source of resources for integration into the Cultural Heritage Cloud in the form of datasets, training materials or vertical applications. They will not only demonstrate the engagement of the wider cultural heritage community with the Cultural Heritage Cloud but provide practical integration examples for validating the Integration Strategy and Roadmap. Within ECCCH Beyond the applications developed with the ECHOES project, the ECHOES community 6 that the Integration Strategy must take into consideration is primarily composed of so-called “sister projects” funded under ECCCH calls. The first three projects were awarded as part of the ECCCH call 2023, topic Innovative tools for digitising cultural heritage objects: • AUTOMATA - focuses on the AUTOMated enriched digitisation of Archaeological liThics and cerAmics. • TEXTaiLES - develops TEXTile digitisAtIon tooLs and mEthodS for cultural heritage. • HERITALISE - explores Heritage Buildings and Objects Digitisation & Visualisation within the Cloud. 5 As described on the ECHOES website: https://www.echoes-eccch.eu/cascading-grants/ 6 See the ECHOES website for more details: https://www.echoes-eccch.eu/community/ ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 17 Building on the foundation of the three initial projects, the 2024 European Collaborative Cloud for Cultural Heritage – Innovative use cases call awarded 10 projects listed below: • MusicSphere - A Multimodal Approach for Digitizing, Analyzing, and Simulating Traditional Musical Organs Through 3D Technologies, Acoustic Analysis and Interactive Experiences • KINETIKA - Advancing the Digitization and Analysis of Dynamic Cultural Heritage Objects • StratiGraph - Knowledge Graphs for Stratigraphy • ARXIVE - Advanced Research and eXploration for Interoperable Value in European Heritage • ECHOLOT - European Cultural Heritage Optimised Linked Open Tools • INFINITY - Multidimensional knowledge-based annotation for ethical context-aware heritage data life cycles • UNICHE - Unified No-Code platform for Interactive Cultural Heritage Experiences • PlaceMUS XR - Digital Journey across Musical Places in Europe and Extended Realities • EXCALIBUR - Advanced toolkits for interdisciplinary and enhanced study, conservation, and restoration in burial excavations and findings • COLOURS - Collaborative On-cloud Lab for the conservation and digital restoration of ColOUred heritage collectionS The diversity of themes and approaches addressed reinforces the need for a strong integration strategy ensuring interoperability by design and clarifying roles and responsibilities from the start (see Section 10 Integration Governance), especially considering that 9 out of these 10 projects include cascading grants schemes. As developed in the section 10 Integration Governance below, while the ECHOES project team provides the integration framework and establishes a close liaison with the sister projects, these projects remain responsible for the integration of their own cascading grants outputs in the ECCCH. Furthermore, additional ECCCH projects will join this group of “sister projects”. At the time of writing, we know that 76 proposals were received for the ECCCH call 2025 on Innovative use cases. The final results will be published in early 2026. It is expected that 8 projects will be funded from this call. While the three first sister projects are already onboarded in the ECHOES Integration Task Force (EITF), and with the next ten projects about to join, several key integration questions have already emerged and are used to structure the present strategy and the accompanying roadmap (D3.2). These include the need to identify resource types (section 8) and offer clear interoperability guidelines (D6.2, January 2026) and integration processes (D3.2, November 2025). Developing the storage and computing resources of the ECCCH under a federated model where not all the resources are provided by the same provider is a question that also needs to be tackled via the technical governance principles (D10.2, May 2026). In general, distinguishing between agreements during and beyond the projects’ lifetime is one of the main challenges discussed by the ECHOES Integration Task Force. ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 18 Beyond ECCCH Beyond ECHOES and the ECCCH framework developed by the European Commission through its calls, “external projects” are also expressing interest in integrating with the ECCCH. Even if the integration of the outcomes of these projects and their communities cannot be prioritised in the same way as the ECCCH projects or ECHOES Cascading Grants projects, they represent an important dimension of the Cultural Heritage Cloud in the making and are considered as potential ECCCH stakeholders. These projects come from a wide range of initiatives, including Horizon Europe, European Strategy Forum on Research Infrastructures (ESFRI), European Research Council (ERC), European innovation Council (EIC), the Gaming Cluster, International Partnership for Cultural Heritage and Innovation (IPCI), the Co-funded European partnership for Resilient Cultural Heritage, the Digital Europe Programme (e.g. Data Space for cultural heritage and 3D4CH), as well as international (e.g. AI4LAM, IIIF), national and regional initiatives. A list of these projects, which is kept up to date by the ECHOES coordination team and includes projects that proactively reached out to the ECHOES team, and projects or initiatives expressing interest during in-person meetings or ECHOES presentations. Based on the work conducted in ECHOES Work Package 4 around the identification of communities and their needs, we expect to refine the understanding of the ecosystem of interest for ECHOES integration by identifying even more projects, initiatives or stakeholders that could tomorrow become actors of the ECCCH. The formalisation of relationships between ECHOES and these external projects and the scope and modalities of their integration could take many forms. Confronted to this diversity and multiplicity, the role of the integration strategy is also to clarify different roles (users vs. providers for example as elaborated in section 10), and to set up mechanisms balancing easy contribution of all interested parties and capacities of the ECHOES consortium (and of the future legal entity) in supporting the integration of resources from these various communities (see section 9). Broader European ecosystem The ECHOES project itself is developing in a context that needs to be highlighted in the integration strategy as it also influences some of the integration principles described above, and as synergies need to be developed with existing EU initiatives - from Data Spaces to Joint Programming Initiatives or Joint Undertakings - to ensure the long-term sustainability of the ECCCH, avoid the duplication of efforts, pool efforts and maximise investments. ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 19 Data Space for Cultural Heritage The Data Space for Cultural Heritage (DS4CH) is inherently a twin initiative with substantial scope complementarity (Cultural Heritage) and consequently very close relations, requiring intensive and continuous information exchange and coordination to identify points of interaction/integration and to delineate the functional scopes of the two initiatives. While many aspects remain under discussion, a consensus is emerging on the main points of the relationship between the two initiatives: • The Data Space serves as a source of metadata for the Cloud Infrastructure by exposing its metadata catalogue as one node of the distributed CH Knowledge Base, making it available for querying by researchers using the Cloud portal and other tools from the ECHOES Application Catalogue. • The metadata contains pointers to the actual CH Digital Objects (content), stored and provided in repositories and services from Cultural Heritage Institutions, so that they are accessible and (re)usable in the research process • Dedicated access services will offer specialised means for retrieving and consuming the metadata and data, such as APIs that support search and export of item-level metadata, as well as packages of custom subsets. European Open Science Cloud (EOSC) The European Open Science Cloud 7 and the emerging EOSC Federation 8 are key initiatives in the European research data landscape. Recognised by the European Commission as the Data Space for Research and Innovation, EOSC additionally provides a bridging function with the common European Data Spaces. As a key initiative offering access to cultural heritage data for scientific research, it is important that ECHOES considers how the Cultural Heritage Cloud will position itself within the EOSC ecosystem. While this is a long-term endeavour, in the framework of the Integration Strategy, it is important that ECHOES considers the alignment with the EOSC technical and interoperability requirements as outlined in the EOSC Federation Handbook 9 . For example, the EOSC Federation provides clear guidelines about the EOSC Authentication and Authorisation Infrastructure (AAI) Architecture 10 , based on the AARC Blueprint Architecture 11 . It is therefore important that ECHOES already considers the EOSC approach to AAI, for the implementation of the ECHOES AAI solution. Such alignment will help facilitate the smooth integration of the Cultural Heritage Cloud into the EOSC Federation should it wish to establish itself as a node in the future. 7 See: https://open-science-cloud.ec.europa.eu/ 8 See: https://eosc.eu/building-the-eosc-federation/ 9 See: https://eosc.eu/building-the-eosc-federation/eosc-federation-handbook/ 10 Kanellopoulos, C., Adomeit, M., Ardizzone, V., Florio, L., Giacomini, F., Groep, D., Hardt, M., Kálmán, T., Kuczyński, T., Liampotis, N., Short, H., Sidorova, I., Michal, Š., & Wierenga, K. (2025). EOSC AAI Architecture 2025 (March 2025). Zenodo. https://doi.org/10.5281/zenodo.15388270 11 See: https://aarc-community.org/architecture/ ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 20 Joint Programming Initiative on Cultural Heritage (JPI CH) The Joint Programming Initiative on Cultural Heritage and Global Change 12 was created in 2010 based on an instrument launched by the European Commission. It is a Member-State-driven initiative bringing together national research funding organisations, ministries, and research councils from Europe to address societal challenges in the framework of the European Research Area (ERA) to tackle the many threats that cultural heritage is exposed to, which, in addition to natural ageing, include climate change and pollution, increasing urbanisation, mass tourism, human negligence, vandalism and terrorism. The JPI CH addresses these challenges by, for example, improving the coordination of research on Cultural Heritage at the EU level by identifying short and long-term needs and priorities, promoting joint and multidisciplinary approaches to Cultural Heritage research and improving knowledge and increasing awareness of citizens, policymakers, and stakeholders. In the first instance, ECHOES has collaborated with the JPI CH regarding the potential integration of resources from projects listed in the Heritage Research Hub in the ECHOES Inventory. Further opportunities for collaboration in the framework of the ECHOES Integration Strategy will be explored in the course of the project. High Performance Computing and AI Factories The state-of-the-art tooling which will be integrated into the Cultural Heritage Cloud ecosytem, will make use of High Performance Computing (HPC) resources and Artificial Intelligence. It is therefore important that ECHOES aligns with and where possible leverages existing initiatives in this area such as the EuroHPC 13 and the emerging AI Factories 14 . There is already considerable interest from communities within ECHOES to make use of compute and storage resources, e.g. for training models for the analysis of cultural heritage artefacts. Assuming this need of providing computing resources is confirmed by the community, ECHOES provision of these resources could (partially) rely on existing EuroHPC or the forthcoming AI factories infrastructure, especially considering that some of consortium partners, like PCSS, are also leading AI Factories 15 . In this context, it is also important to consider the tensions between commercial and and public sector computing provision. 12 See: https://www.heritageresearch-hub.eu/joint-programming-initiative-on-cultural-heritage-homepage/jointprogramming-initiative-on-cultural-heritage-about/ 13 See: https://www.eurohpc-ju.europa.eu/index_en 14 See: https://www.eurohpc-ju.europa.eu/ai-factories_en 15 See the description of the PIAST-AI Factory: https://www.eurohpc-ju.europa.eu/ai-factories/poland_en ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 21 ESFRI Research Infrastructures and related initiatives European Research Infrastructures (RIs) are strategic contributors to the Europe Research and Technology Infrastructure ecosystem 16 . The European Strategy Forum on Research Infrastructures (ESFRI) 17 ensures that the European Research Infrastructures landscape remains coherent and carries out regular RIs landscape analysis while also evaluating, reviewing and monitoring EU RIs. Three ERICs from the Social Sciences and Humanities domain are partners of the ECHOES project - DARIAH, CLARIN and E-RHIS - ensuring that their expertise and infrastructure, including the data, tools and workflows contributed and used by their community can be leveraged for the benefits of the future ECCCH. In addition to their establishment as European legal entities – European Research Infrastructure Consortia or ERICs 18 - DARIAH, CLARIN and E-RHIS are also working towards a more harmonised data and services landscape, for example by sharing services provision when they benefit to their user base, and by collaborating through the SSH Open Cluster, one of the five science clusters 19 operating within the context of the European Open Science Cloud (EOSC) to foster the uptake of Open Science practices in Europe. National Initiatives across Europe At the national level, key initiatives are also funded that are very relevant to the ECHOES ecosystem, as they bring together major actors from the Cultural Heritage sector and pull together national resources for the benefits of the national users. There is a wide diversity of these national initiatives, however, the goal here is not to provide an exhaustive inventory, but rather to highlight some of the specificities that the ECHOES Integration Strategy must tackle – see next section – when it comes to their potential integration to the ECCCH. The French initiative ESPADON focusing on the Heritage Science, and on supporting dynamic analysis of ancient and digital objects 20 aims, for example, by 2028, to create a network of platforms, facilities, instruments and expertise, at establishing a common framework for data management and archiving, especially by enabling the creation of “augmented CH objects”. In Italy, the H2IOSC project brings together the national representations of 4 major ERICs - CLARIN-IT, DARIAH-IT, E-RIHS.it and OPERAS-IT - with the ambition of establishing itself as an EOSC node. H2IOSC will provide its users with an ”open and multidisciplinary environment that enables access to advanced tools for conducting innovative and computationally intensive research on complex digital data and objects” 21 . In Germany, the data infrastructure landscape, mostly structured via the national research data infrastructure (NFDI, Nationale Forschungsdateninfrastruktur), 16 See: https://research-and-innovation.ec.europa.eu/strategy/strategy-research-and-innovation/our-digitalfuture/european-strategy-research-and-technology-infrastructures_en 17 See: https://www.esfri.eu/forum 18 See: https://research-and-innovation.ec.europa.eu/strategy/strategy-research-and-innovation/our-digitalfuture/european-research-infrastructures/eric_en 19 See: https://science-clusters.eu/ 20 See: https://espadon.net/ 21 See: https://www.h2iosc.cnr.it/the-project/ ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 22 established several thematic consortia, including one particularly relevant for the ECCCH context: the NFDI4Culture, the Consortium for Research Data on Material and Immaterial Cultural Heritage. Through this consortium, the German community establishes a needs-based infrastructure covering all the stages of the data lifecycle for a wide range of research data (from architecture, art history and musicology to theatre, dance, film and media studies) 22 . Finally, the last example is the UK initiative RICHeS (Research Infrastructure for Conservation and Heritage Science) programme, that funds, for example, the Heritage Science Data Service (HSDS) that offers unified access to services and data, as well as a collection aggregator, repository and a suite of VREs. These examples illustrate the diversity of national initiatives, scientific or technical scope covered, as well as funding mechanisms involved in their development and envisioned sustainability. While it is important for the future ECCCH to rely on these existing building blocks to set up its infrastructure and its service and data offer, the inherent national dimensions of these initiatives also carry challenges such as the need to scale up services initially developed to support a smaller user-base than the one the ECCCH targets to address and importantly the availability of nationally funded resources to users from other countries. The ECHOES ecosystem presented in this section presents itself as diverse and complex. Resources created or used in different contexts – by projects or already sustained and maintained by wellestablished institutions – presenting different maturity levels have to be integrated in the ECCCH. And potential ECCCH providers are identified as actors ranging from local/regional institutions to large scale clusters of EU infrastructures. While this possibility to build on the existent represents a strength for the ECCCH infrastructure that does not have to be built from scratch, hence the federation approach chosen, it also means that to address/face this heterogenous landscape the ECCCH Integration Strategy must ensure an inclusive and flexible framework. This strategic framework is presented in the next section. 22 See: https://nfdi4culture.de/index.html ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 23 9. ECCCH Integration Strategy: Building the Federated Digital Commons The European Collaborative Cloud for Cultural Heritage (ECCCH) is not a central repository; it is a federated ecosystem connecting distinct nodes (national/regional clouds, institutional data centres, and the central hub, which itself is also federated). To achieve this, the integration strategy moves beyond simple file hosting to create a Distributed Data Fabric and beyond simple applcation cataloguing to create a live ecosystem of tools, applications and services that can scale, learn and work collaboratively for and with the users. This strategy is designed to guide the transition from isolated project outputs to a cohesive, distributed and federated Digital Commons for Cultural Heritage. It defines how different resources, such as Data and Metadata, Applications and Services, and Workflows evolve across three levels to support this architecture, with specific attention to provenance (where data comes from) and quality (how reliable it is), and how Integration Units (IU) consisting of a “resource-cloud component pair” are used as a structuring concept to navigate the Integration Roadmap. Integration Units (IU) An Integration Unit is defined as a pair consisting of a resource to be integrated to the Cultural Heritage Cloud and a Cloud component to integrate with. For a given resource, it could be that multiple integration units are needed. For example, an application could need to integrate with the ECCCH AAI and with the Knowledge Base. This would be considered as two different Integration Units. The processes leading to the identification of these Integration Units is described in detail in the Integration Roadmap. Breaking down contributions from the ecosystem to Integration Units is necessary to capture their diversity, to offer a unified but flexible integration framework, and to easily track progresses of numerous integration activities running in parallel across the many different actors involved. Levels of integration The integration strategy accompanies partners while navigating the complex integration landscape by suggesting three different levels/types of integration depending on the operation mode, the maturity and the target of each organization wishing to contribute one or more integration units to the Cloud. Each phase represents a significant leap in how resources interact with the Cloud's core components, such as the Knowledge Base or the Authentication and Authorisation Infrastructure (AAI). • Level 1: Tactical Integration (“The Connected Storage Strategy”) Strategic Goal: The primary objective at this level is critical mass and visibility. We aim to lower the entry barrier for institutions to bring their assets onto the Cloud. Strategically, this phase focuses on ingestion and storage efficiency rather than deep computational interoperability. ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 24 Catalogue Federation: The core node holds a pointer (URL) to the data, but the data remains stored in its original location, which can be outside of the Cloud. • Level 2: Strategic Integration ("The Interoperability Strategy") Strategic Goal: The objective shifts to meaning and connection. We move from pointing to the data, to understanding what it represents. Strategically, this level enforces the adoption of the Heritage Digital Twin Ontology (HDTO), ensuring that a dataset from Italy can be semantically aligned with a dataset from France, as well as implementation of unified APIs to access the distributed datasets. Hybrid Federation: Users search centrally but retrieve data via standardized APIs from member nodes. This creates a unified "search experience" even if the data storage is distributed. • Level 3: Transformational Integration ("The Digital Commons Strategy") Strategic Goal: The ultimate goal is automation, autonomy, and distributed trust. We transition from a repository to a Distributed Data Fabric where applications, services, data and workflows are dynamically federated, scaled and actioned or used. Strategically, this level enables Federated Compute, moving algorithms to the data or if needed, moving data to the algorithms. Full Federation (including full mesh & edge computing): o Compute Federation: The Resource Manager can deploy a Level 3 "App" to any node where data resides to minimize latency (Edge Computing). o Cross-Node Orchestration: A single workflow can transparently trigger ingestion in France, processing in Italy, and publishing in the Central Hub. o Sustainability: By relying on the logic (Workflows) but distributing the storage, institutions maintain ownership of their data while benefiting from shared cloud intelligence. ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 25 The Central Role of the Heritage Digital Twin (HDT) The Heritage Digital Twin is the primary "citizen" of the ECCCH ecosystem. It differs from standard data because it combines computable data (e.g., geometry, text, audio) with semantic knowledge (e.g., history, context, relationships) governed by the Heritage Digital Twin Ontology (HDTO). The integration process essentially transforms a passive digital record into a (dynamic) HDT. The HDT Creation Lifecycle The three integration levels correspond directly to the maturity and capability of the Digital Twin within the Cloud. Integration Level Status of the Digital Twin Description of the "Twin" State Level 1: Tactical (Ingredients of the HDT) The "Potential" Twin Fragmented Assets. The Cloud holds the raw materials (point clouds, historical manuscripts, chemical analysis logs), along with their metadata descriptions. These are discoverable files but are not yet an HDT because they lack the semantic glue to be machine-readable as a unified entity. Level 2: Strategic (Assembly of the HDT) The "Semantically Valid" Twin Structured Entity. The partner maps their data to the HDTO. The raw assets are linked to create a coherent digital object. The Twin can now be queried semantically (e.g., "Show me all Amphorae from 500 BC found in this region"), but it is largely a container of the different elements. Level 3: Transformational (Living HDT) The "Dynamic" Twin Dynamic Agent. The HDT is fully synchronised with the Cultural Heritage Cloud. It can trigger workflows (e.g., auto-updating its condition report based on new sensor data). It is enriched by AI services running in the cloud and can interact with other HDTs in the federation. Table 1: Digital Twin integration levels Provenance and Quality: The "Paradata" For a Digital Twin to be scientifically valid, the integration strategy must enforce rigorous paradata (documentation of the processing steps). • Level 1: User uploads a narrative workflow, a PDF or alike, describing how the 3D scan was prepared (manual). ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 32 10.Integration Governance In order to ensure clear and transparent decision-making in relation to the ECHOES Integration Strategy and Roadmap it is important that ECHOES integration activities are embedded into the overall ECHOES Governance Structure 24 . An overview of the ECHOES Governance Structure is provided below: Fig. 2 ECHOES Governance Structure Stakeholders Council Firstly, as part of the Governance layer of the overall ECHOES organisational structure, the Stakeholders Council (StaC) has been established to bring together representatives from the other ECCCH-funded projects and European initiatives related to Cultural Heritage. The StaC provides advisory support to the ECHOES General Assembly and a structural forum to facilitate the strategic integration of the broader community of stakeholders into the ECCCH ecosystem, as well as to oversee the ECHOES integration activities at a strategic level, for example, contributing to the development of and providing feedback on the ECHOES Integration Strategy. The first meeting of the Stakeholders Council will take place in March 2026 during the ECHOES Annual Event in Poznan. After which a regular feedback loop between the StaC and the ECHOES Integration Task Force will be established to facilitate the strategic and sustainable integration of ECCCH-sister projects and related initiatives into the Cultural Heritage Cloud. 24 See the ECHOES website dedicated section for more details: https://www.echoes-eccch.eu/governance/ Rodier, X., Gadoin, L., Sampaio, M., & CNRS. (2025). ECHOES Quality and Risk Management Plan (D1.3). Zenodo. https://doi.org/10.5281/zenodo.17600734 ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 33 ECHOES Integration Task Force While ensuring the provision of regular updates to the ECHOES Stakeholder’s Council, the day-to-day activities integration activities are coordinated by ECHOES Integration Task Force (EITF). The EITF, led by ECHOES project partners DARIAH-EU and CNRS-CY Cergy Paris University, is a dedicated Task Force at the level of the ECHOES Project Team, which was initiated at the start of the project. It is composed of ECHOES Work Package Leaders, from the Coordination Team (WP1), the Communities (WP4) and Capacity Building (WP5) work packages, as well as the technical work packages Cloud Environment (WP6), Digital Commons Knowledge Base (WP7) and Vertical Applications (WP8) plus the Cloud Assessment Framework work package (WP9). Other experts are invited as required. The EITF coordination is undertaken jointly by WP1 (T1.5 Managing and coordinating the project’s technical development and infrastructure) and WP3 (Enhancing Collaboration and Integration). In addition to the ECHOES project partners, representatives from the ECCCH sister-projects may also be invited to EITF meetings. These meetings are essential to oversee the integration activities across the ECHOES ecosystem. The key roles and Terms of Reference of the EITF are outlined as follows. Firstly, the EITF forms a transversal structure within the ECHOES project team to ensure join-up between the work packages, in particular bridging the communities and technical areas of the project. Secondly, the EITF forms a structural framework for coordinating integration activities together with the ECHOES-sister projects. To support these activities, the EITF is responsible for designing and developing both the ECHOES Integration Strategy and Roadmap, as well as monitoring its activities and progress. Managing the roadmap The ECHOES Integration Roadmap (D3.2) describes an initial set of processes to operationalise the Integration Strategy. The day-to-day management of the Roadmap is undertaken by the EITF Coordination Team who provide regular feedback to the ECHOES Integration Taskforce. The following subsections introduce the two key building blocks used in the Integration Roadmap: a) Integration Roles and b) Integration cycles. Finally, integration risks with related mitigation actions as well as integration metrics will be identified, monitored and iterated during the course of the project in close collaboration with the ECHOES Integration Task Force. ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 34 Integration roles First of all, given the broad collaborative dimension of the ECCCH and the involvement of many diverse stakeholders, it is essential to define a set of Integration Roles that can be applied across all integration use cases. These roles, outlined below, are also used to model the processes in D3.2. The guiding principles behind this role attribution is to establish a balanced relationship between ECHOES and the projects or initiatives that must – or wish to - integrate with the ECCCH, so that integration efforts are distributed as evenly as possible. While the ECHOES team is tasked with developing the initial ECCCH infrastructure and provide the necessary information for other stakeholders to integrate with it, the ECCCH sister projects and projects or initiatives from the wider ECHOES ecosystem remain responsible for the resources they contribute. Based on this principle, the following roles support coordination and implementation of all integration activities, are anticipated. On the consumers’ side, e.g. a specific ECCCH-sister project: • ECHOES adopter representative = a representative of a project or initiative willing to integrate with ECHOES. For ECCCH-sister project, a representative is a member of the StaC and will be invited to EITF meetings as required. • ECHOES adopter technical contact(s) = the individual(s) responsible for the specific resource to be integrated. On the ECHOES side: • ECHOES cloud components providers = partners in charge of developing and/or providing an ECHOES Cloud Component that can be integrated with. • ECHOES WP leaders = the team leaders of the ECHOES work package responsible for facilitating the integration activities. • EITF coordination team = this team is composed of DARIAH and CNRS-CYU coordinating the EITF, in close liaison with the CNRS, coordinator of the project, and with the support of other ECHOES project team members as required. Once established (November 2026), the possibility of including the management of integration-related activities via the ECHOES Service Desk will be explored. As highlighted in the initial sections of the Integration Governance, both sides (adopters and ECHOES team) are united in the EITF, and thanks to this set-up, ECHOES adopters can also influence the overall direction of the Integration Strategy and Roadmap. ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 35 Integration Cycles Secondly, a central element for enabling an iterative approach to integration activities is the concept of “integration cycles”. Organising and managing these cycles is at the core of the Integration Governance: the established cadence helps manage groups of incoming projects, allow for regular review and adjustment of processes, and provides regular metrics reflecting the diversity of the integration cases that will emerge. Firstly, resource integration into the ECHOES ecosystem follows an agile and iterative process based on a three (to six)-month cadence. This cycle is not a strict delivery deadline, rather, it provides a strategic time-box structure for planning, executing, and reviewing integration tasks. Each cycle ends with a checkpoint during which the EITF assess progress, resolve obstacles, and adjust priorities for the next period. This cadence-based model is designed to manage the expected volume, diversity and complexity of the integrations to be undertaken. A foundational principle of the integration roadmap is the unit of integration, defined as pairs consisting of resources (e.g. datasets, tools, services) from the ECHOES adopter and of an ECHOES Cloud Component. This resource-based approach combined to the units of integration allows the EITF to prioritise effectively (also based on the release dates of the major cloud components) and maintain predictable progress across diverse integration efforts. Finally, as part of the implementation of the roadmap, ECHOES will identify and monitor integration risks with together related mitigation actions, which will be maintained in a risk register as part of the project. Furthermore, ECHOES will be able to demonstrate the breadth, depth, diversity, and granularity of integrations realised through a series of integration metrics complemented by integration examples. The design and implementation of these metrics, alongside the identification and mitigation of risks, will be undertaken, in close collaboration with the ECHOES Integration Task Force, during the project. ECHOES Project 101157364 – Deliverable 3.1 ECHOES Integration Strategy for datasets, tools and workflows 36 Conclusion The ECHOES Integration Strategy represents a foundational step in the realisation of the Cultural Heritage Cloud, setting the goals and establishing a cohesive framework for connecting resources across Europe and beyond in a federated environment. By focusing on the integration of resources, rather than individual projects, the strategy provides a clear methodology to incorporate the diversity of cultural heritage initiatives across Europe, maximising the reuse of existing cultural heritage assets and project results. This resource-centred approach allows for a scalable and flexible platform and technical architecture. The three strategic pillars presented here, and the guiding integration principles sourced from them, offer a structured way to navigate the diversity and complexity of the cultural heritage landscape, as visualised by the ECHOES ecosystem and to support decision-making. In addition, the multi-level integration framework ensures inclusivity and accommodates the diverse capacities of the various stakeholders. Central to the strategy is the emphasis on community engagement, enabled by an inclusive model of Integration Governance and by the iterative nature of both the ECHOES Integration Strategy and its companioned Roadmap. The definition of clear roles and responsibilities as part of the Integration Governance model is crucial to the success of the integration activities. By establishing the Stakeholders Council and the ECHOES Integration Task Force, ECHOES ensures that integration decisions are informed, transparent and collective, reinforcing the legitimacy of the Cultural Heritage Cloud and supporting refinement based on shared experiences. Its iterative design ensures that the strategy will continue to evolve, responding to the evolution of the cloud architecture and components development themselves as well as to the refinement of the community needs as gathered all along the ECHOES project lifetime. In addition to the technical sustainability outlined in section 9, the need to continue integration activities after the end of the ECHOES project, once the Cultural Heritage Cloud becomes a sustainable long-term cultural heritage data infrastructure, supported by its own legal entity, has already been anticipated. Once the ECHOES Integration Roadmap is established and functions smoothly, at around May 2027 (M36 of the project), the ECHOES Integration Task Force, in close relationship with the Stakeholder Council and the wider ECHOES Governance Structure, will initiate discussions as to how integration activities can continue beyond the formal end of the ECHOES project. These discussions will need to be undertaken in close collaboration with WP10 Cloud Governance and WP11 Long-term Sustainability. Finally, by the end of the ECHOES project, the Cultural Heritage Cloud will have been established, including its related legal entity, as a first significant milestone towards the long-term sustainability. The ECHOES Integration Strategy and related Roadmap are fundamental building blocks in making the Cultural Heritage Cloud a reality. 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