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  • Book
  • Open Access
  • © 2021

The Once-Only Principle

The TOOP Project

  • This book is open access, which means that you have free and unlimited access.

  • It describes and documents the developments and results of the Once-Only Principle project (TOOP)

  • The TOOP project was funded by the EU Framework Programme for Research and Innovation

Part of the book series: Lecture Notes in Computer Science (LNCS, volume 12621)

Part of the book sub series: Information Systems and Applications, incl. Internet/Web, and HCI (LNISA)

Buying options

Softcover Book USD 49.99
Price excludes VAT (USA)

Table of contents (12 chapters)

  1. Front Matter

    Pages i-x
  2. The Once-Only Principle: A Matter of Trust

    • Robert Krimmer, Andriana Prentza, Szymon Mamrot, Carsten Schmidt
    Pages 1-8Open Access
  3. Implementation of the ‘Once-Only’ Principle in Europe – National Approach

    • Szymon Mamrot, Katarzyna Rzyszczak
    Pages 9-37Open Access
  4. Drivers for and Barriers to the Cross-border Implementation of the Once-Only Principle

    • Nele Leosk, Irma Põder, Carsten Schmidt, Tarmo Kalvet, Robert Krimmer
    Pages 38-60Open Access
  5. Once-Only Principle Good Practices in Europe

    • Maria A. Wimmer
    Pages 61-82Open Access
  6. TOOP Trust Architecture

    • Luca Boldrin, Giovanni Paolo Sellitto, Jaak Tepandi
    Pages 126-140Open Access
  7. The Technical Challenges in OOP Application Across the European Union and the TOOP OOP Architecture

    • Jaak Tepandi, Carmen Rotuna, Giovanni Paolo Sellitto, Sander Fieten, Andriana Prentza
    Pages 141-163Open Access
  8. Testing Methodology for the TOOP Pilots

    • Andriana Prentza, Marie-Laure Watrinet, Lefteris Leontaridis
    Pages 164-190Open Access
  9. TOOP Pilot Experiences: Challenges and Achievements in Implementing Once-Only in Different Domains and Member States

    • Andriana Prentza, David Mitzman, Madis Ehastu, Lefteris Leontaridis
    Pages 191-207Open Access
  10. Measuring the Impact of the Once Only Principle for Businesses Across Borders

    • Tjerk Timan, Anne Fleur van Veenstra, Kristina Karanikolova
    Pages 208-224Open Access
  11. The Future of the Once-Only Principle in Europe

    • Robert Krimmer, Andriana Prentza, Szymon Mamrot, Carsten Schmidt, Aleksandrs Cepilovs
    Pages 225-236Open Access
  12. Back Matter

    Pages 237-241

About this book

This open access State-of-the-Art Survey describes and documents the developments and results of the Once-Only Principle Project (TOOP). 

The Once-Only Principle (OOP) is part of the seven underlying principles of the eGovernment Action Plan 2016-2020. It aims to make the government more effective and to reduce administrative burdens by asking citizens and companies to provide certain standard information to the public authorities only once.

The project was horizontal and policy-driven with the aim of showing that the implementation of OOP in a cross-border and cross-sector setting is feasible. The book summarizes the results of the project from policy, organizational, architectural, and technical points of view.


  • access control
  • communication systems
  • computer systems
  • cryptography
  • databases
  • Field Programmable Gate Array (FPGA)
  • gateways (computer networks)
  • information systems
  • internet protocols
  • network protocols
  • object-oriented design
  • object-oriented programming
  • object-oriented programming languages
  • signal processing
  • social networks
  • software architecture
  • software design
  • software engineering
  • system architectures

Editors and Affiliations

  • TalTech Tallinn University of Technology/University of Tartu, Tallinn/Tartu, Estonia

    Robert Krimmer

  • University of Piraeus, Piraeus, Greece

    Andriana Prentza

  • Łukasiewicz Research Network – Institute of Logistics and Warehousing, Poznan, Poland

    Szymon Mamrot

Bibliographic Information

Buying options

Softcover Book USD 49.99
Price excludes VAT (USA)