Articles

At work, I connect business and IT using a variety of experiences and knowledge gained in different areas of activity – from testing, through analysis and requirements engineering, to process management.
Outside of my professional career, I am involved in a number of non-profit activities aimed at improving software development methods and I am an active member of several organizations acting to increase knowledge and maturity of requirements engineering and QA community.
Between 2011 and 2013 I was an active member of REQB® Board. Today, I continue work on RE standardization in IREB®. I am one of the main authors of IQBBA® certification scheme for business analysts and co-author of ISTQB® Acceptance Testing certification program.
From March 2018 to May 2020 I was president of Polish Testing Board (SJSI). Since March 2018 I am a member of the Executive Board at IREB®.

• The importance of active listening in the role of a Business Analyst

Prof. Dr. Salinesi is an active academic who teaches topics in relation with software design such as Requirements Engineering, and Software Product Lines. He was involved in many funded research projects (FP4, FP5, H2020, ANR) and was the leader for collaborations and consultancy works for various companies such as France Télécom, SNCF, Renault, EDF or REXEL). He has been General Chair of SPLC, CAiSE, REFSQ international conferences, and was Organizing Chair of the 13th IEEE International Conference on Requirements Engineering.

At IREB, Prof Salinesi has acted for 2 mandates as Second Chair of the Executive Committee. He is now Full Member, member of the Editorial Board, and WG Member.

• Conversation with an Artificial Intelligence

For more than twenty years, Rainer Grau has accompanied companies on their way enterprise agility. He supports companies in their efforts to continuously develop and create sustainable value for customers and employees. For him, it is particularly exciting to find out which methods, techniques and approaches are suitable for scaling agility and building the right product and the right service for the customer. Business analysis and requirements engineering are two essential disciplines in this context, which also generate high value in an agile setup - even if perhaps lived completely differently compared to a classic project approach.

Rainer's background of experience in business agility is based on his consulting work with companies from various industries. Stages of his professional life include Distinguished Consultant and Partner at Zühlke Engineering, Head of Business Development at digitec Galaxus, responsible for courses at universities of applied sciences on the topic of agility, founder of the Swiss Agile Leaders Circle, founder of Denkplan Verein and active involvement in communities around agility, business analysis and requirements engineering.

If there is still time left, Rainer Grau likes to spend it with his family, doing sports, playing his guitar and reading novels.

• Mission Possible
• Innovation Arena

Gil Regev has been a researcher at EPFL since 1997 in the fields of enterprise information systems, requirements engineering, change management and knowledge management. Since 2008 he is also manager and consultant at Itecor, a boutique consultancy firm. Previously Gil developed software for computer peripherals at Logitech, in Switzerland and California.

• A General Systems Thinking Perspective on the CPRE

Alain Wegmann is a full professor at the School of Computer and Communication Sciences, EPFL, Switzerland. He worked 14 years for Logitech (Switzerland, Taiwan, US) in positions ranging from software developer, IS manager, manufacturing engineering to VP of engineering and OEM marketing before joining the EPFL in 1997. His teaching, consulting and research are in the fields of enterprise architecture, requirements engineering and service engineering.

• A General Systems Thinking Perspective on the CPRE

Olivier Hayard has been a consultant and in charge of IT and Knowledge Management at Itecor, a boutique consultancy firm, since 1993. Olivier’s main interests are business analysis and requirements management, as practitioner, trainer and researcher.

• A General Systems Thinking Perspective on the CPRE

Till-J. Faßold is Expert Strategic Planning at 1&1, Germany. In this role – besides other responsibilities – he coaches professionals from various departments and is responsible for the requirements engineering processes. Till-J. Faßold hold a master’s degree in information management from the University of Koblenz and is certified to the IREB CPRE Expert Level.

• Requirements Engineering and Domain Knowledge

Freelance trainer and consultant in Software Engineering. 20 years of work experience, including 7 years as consultant and project manager, 10 years in research and university teaching, and two guest professorships. Associate member at IREB, co-author of syllabus and handbook for the CPRE Advanced Level in Requirements Management. www.herrmann-ehrlich.de

• Requirements Engineering in Job Offers

Maya Daneva, PhD, is Senior Member of Scientific Staff in the Services and Cybersecurity group at the University of Twente, the Netherlands. Her research interests are requirements engineering for large systems, security requirements engineering, requirements-based project estimation, user feedback analytics, and empirical research methods. Maya has a strong international exposure having spent two years of her career in Germany at the University of Saarbruecken and in the IDS Scheer, and 9 years as a business process analyst for SAP Enterprise Recourse Planning projects at TELUS Corporation, Canada’s second largest telecommunication company.

• Requirements Engineering in Job Offers

Chong Wang is an assistant professor at Wuhan University. She has over 10 years of work experience in research and university teaching. Her research interests include requirements engineering, software engineering, and service computing.

• Requirements Engineering in Job Offers

Nelly Condori-Fernandez is an assistant professor at the Universidade da Coruna (Spain) and research associate of the Vrije Universiteit Amsterdam (The Netherlands). Her research focuses on topics related to quality requirements prioritization and sustainability. She has published 85 articles in indexed journals and ranked conferences. Besides, she has been involved in several European projects.

• Requirements Engineering in Job Offers

Suzanne Robertson is having a stellar career in information technology and systems engineering. Suzanne is a pioneer in adapting ideas from other domains for automated solutions. She has collaborated in workshops using experts from fields as diverse as modern music, visualization, and cookery. Ideas from these domains were adapted to make major breakthroughs in creative ideas for domains ranging from air traffic control to local government. She is co-author of the best-selling Mastering the Requirements Process, among other books and courses. She is co-creator of the Volere requirements techniques. She was the founding editor of the Requirements Column in IEEE Software.

• Integrating Business Events into your Agile Framework
• How Will It Work?

As a principal and founder of The Atlantic Systems Guild, James Robertson is known for his work in implementing systems engineering principles that link business specialists with solution specialists. James is a consultant, lecturer, author, project leader whose area of concern is the requirements for software, and the contribution that good business analysis makes to successful projects. James is co-author of 5 books that have been influential in the business analysis world. His training as an architect has led to his work on good design principles and to his focus on how innovation can be integrated with business analysis.

• Integrating Business Events into your Agile Framework
• How Will It Work?

Daniel Méndez is an Associate Professor for Software Engineering at the Blekinge Institute of Technology, Sweden and Senior Scientist at fortiss, the research institute of the Free State of Bavaria for software-intensive systems and services. His research is on Empirical Software Engineering with a particular focus on interdisciplinary, qualitative research in Requirements Engineering and its quality improvement. He regularly publishes in various software engineering publications and has occupied several key positions in venues of the empirical software engineering community. He is a member of the ACM, the IEEE Computer Society, and the German association of university professors and lecturers, and he serves as the representative to ISERN, the International Empirical Software Engineering Research Network. Further information is provided at www.mendezfe.org.

• What is the Relevance of Requirements Engineering Research to Practitioners?
• Modeling Requirements and Context as a means for Automated Requirements Validation

Xavier Franch is Professor at the Universitat Politècnica de Barcelona (UPC-BarcelonaTech), Spain. He is Council Member and Full Member of the IREB association. He has published over 200 peer-reviewed papers in conferences and journals, many of them related to requirements engineering. He was Program Co-Chair of the RE’16 and REFSQ’11 conferences, and he belongs to the Editorial Board of the Requirements Engineering Journal (Springer) and Information Software and Technology (IST) journals, among others. He is coordinator of the Q-Rapids project and participates in the OpenReq project, both in the H2020 programme. He organizes workshops concerning requirements engineering for NLP4RE, CrowdRE, JIT-RE and others.

• What is the Relevance of Requirements Engineering Research to Practitioners?
• Modeling Requirements and Context as a means for Automated Requirements Validation

Andreas Vogelsang is a post-doc researcher in the software & systems engineering group at the Technical University of Munich. He works on model-based requirements engineering and participated in several research collaborations with industrial partners especially from the automotive industry. His research published was published in relevant international conferences like RE, REFSQ, or ICSE.

• What is the Relevance of Requirements Engineering Research to Practitioners?
• Modeling Requirements and Context as a means for Automated Requirements Validation

David Gilbert has worked in various operational and strategic Digital Design roles since 2007. Previously, he completed his studies as Diploma Mediamanager at the Wiesbaden University of Applied Sciences.

Until 2015, he worked for various design agencies such as Scholz & Volkmer, Pixelpark, Mutabor or SinnerSchrader. The projects he has worked in have received over 25 international and national design awards. - Since 2015 he is working in the IT department of the Deutsche Bahn Group, where he holds the role of Chief Architect User Experience at the intersection of classic system-oriented and user-oriented software conception.

From 2011 - 2016, he was a lecturer in UX Design at the RheinMain University of Applied Sciences, and has published various contributions to the topics of strategic UX design and digital design.

In addition to his engagement within the "Digital Design" working group, he is chairing the Bitkom "Digital Design" working group as well as he is a member of the "Designforum Digital Experience" of the German Design Council.

• Mastering Business Requirements

Dirk Röder has been working in software engineering since 1992. At DB Systel GmbH, he has been chief software architect since 2007, taking care of the employees involved in IT conception.

Since 2010, he has played a leading role in setting up and further developing the internal training program for the conceptual design of software. He has been driving the integration of UX design and classic software engineering since 2015. He is currently working on the conversion of concept work to agile implementation and new production models such as DevOps.

• Mastering Business Requirements

Rana Siadati is currently a PhD student in Software Requirements Engineering and also a visiting lecturer by the School of Computer Science at the University of Hertfordshire. Alongside these roles, Rana has many years of academic and industrial experience, also at managerial level, gained in the UK and abroad.

• Learning from history: The case of Software Requirements Engineering

Paul Wernick is a Senior Lecturer in Computer Science at the University of Hertfordshire. Dr Wernick has taken leading roles in the ProSim series of software process simulation workshops, and the IEEE Workshop on Software Evolvability. Dr Wernick’s current research interests cover the high-level human environment within which software processes occur and their simulation, and computer security.

• Learning from history: The case of Software Requirements Engineering

Vito Veneziano is a Senior Lecturer in Computer Science at the University of Hertfordshire, and his interests range from software engineering, HCI, requirements analysis and system modelling, to how software systems impact on organisations. Previously Dr Veneziano worked in IT and project management, business application development, software design and consultancy.

• Learning from history: The case of Software Requirements Engineering

Priyank Arora is a Senior Business Analyst working in the digital IT space for 12+ years. He is a CBAP certified professional with a Core Credential in Business Analytics from Harvard Business School. He works on large scale digital transformation projects for the world’s leading travel group, where he helped to transition the requirement engineering processes from traditional to Agile working methodologies. He was also involved with a machine learning initiative within his organisation and is a data science enthusiast with an interest in applying analytical thinking and decision automation for business growth.

• Data Science – the expanding frontier for Business Analysts

Jason Hansen obtained a BS in Chemical Engineering from Michigan Tech. He left the work force in 2005 to focus on raising an adopted special needs daughter. In 2015, he decided to return to school and obtained his AAAS in Network Admin. He is working as a tutor at GRCC while pursuing a Master’s Degree in Computer Software Engineering at GVSU.

• Challenges in the elicitation and determination of precise requirements from animal stakeholders

Thijmen works as IT architect at Kommuninvest acting as technical lead for its digitalization initiative and growing CI/CD and Agile practice in the company. His work on the mini-QAW started in his role as researcher at ABB, where he worked on software architectures with colleagues around the globe. He authored publications at leading international software conferences, receiving two best paper awards. Thijmen graduated cum-laude in software engineering from VU University in the Netherlands and Malardalen University in Sweden.

• Discover Quality Requirements with the Mini-QAW

Michael Keeling is a software engineer at LendingHome and the author of Design It! From Programmer to Software Architect. In his career so far, he has worked on a variety of interesting software systems including IBM Watson, enterprise search applications, financial platforms, and Navy combat systems. Michael has a master’s degree in software engineering from Carnegie Mellon University and a bachelor’s degree in computer science from the College of William and Mary. Contact him via Twitter @michaelkeeling or his website, https://www.neverletdown.net

• Discover Quality Requirements with the Mini-QAW

Will Chaparro is a software development manager in IBM’s Watson Group. He spent over 5 years designing and building complex enterprise search solutions as a managing consultant. Prior to IBM he spent 11 years as a software engineer. He has a BS in Computer Science from the University of Pittsburgh.

• Discover Quality Requirements with the Mini-QAW

Freelance trainer and consultant in Software Engineering. 20 years of work experience, including 7 years as consultant and project manager, 10 years in research and university teaching, and two guest professorships. Associate member at IREB, co-author of syllabus and handbook for the CPRE Advanced Level in Requirements Management. www.herrmann-ehrlich.de

• Requirements Engineering in German Job Advertisements

Student of Informatics Teaching at the University of Heidelberg.

• Requirements Engineering in German Job Advertisements

Marie Garnier is an associate professor in the English Department at the Université Toulouse 2 – Jean Jaurès (Toulouse, France). She holds a PhD in English linguistics on the topic of automatic grammar checking. Her research interests include the interface between syntax and lexical semantics in English, the definition and processing of errors produced by English learners, and linguistics-driven NLP. She can be reached at mgarnier@univ-tlse2.fr.

• Detecting Incoherent Requirements in Large Documents
• Improving the Use of English in Requirements
• LELIE

Patrick Saint-Dizier, PhD, is a senior researcher in Computational Linguistics and Artificial Intelligence at CNRS, IRIT, Toulouse, France. He is specialized in discourse and semantic analysis. He has developed several national and European projects dedicated to logic programming, argumentation and technical text analysis. He is the author of several conference and journal articles and of 11 books. Besides foundational research, he has a long practice and experience of research and development activities. Contact: stdizier@irit.fr

• Detecting Incoherent Requirements in Large Documents
• Improving the Use of English in Requirements
• LELIE

Eduard C. Groen is engineering psychologist. His fascination with the rapid rise of man-machine interfaces and other changes that affect society inspires him to contribute with technologies that optimally make use of the potential that these developments bring. As Fraunhofer IESE operates at the intersection of science and industry, he is involved in a variety of projects, while leading the development of the “Crowd-based Requirements Engineering” approach.

• How Requirements Engineering can benefit from crowds

Matthias Koch studied computer science with a focus on software engineering. Since 2012, he is employed as engineer at Fraunhofer IESE and mainly addresses the topics of requirements engineering and business analysis. In this context, he was involved in research projects on the pre-project and requirements definition phase, case studies and product evaluations. In research as well as industry projects, he regularly acts as requirements responsible, conducts workshops with customers and provides consulting.

• How Requirements Engineering can benefit from crowds

Dr. Christine Grimm works for SAP as Senior Researcher in large scale, publicly funded projects. Formerly, she has been employed as a consultant implementing Enterprise Resource Planning Systems in Europe.
She holds a Master of Science in Management as well as a PhD in Science, Technology and Innovation Studies from the University of Edinburgh. She lives with her family in Zürich.

• Requirements Engineering in Research Projects: Food for Thought

Onur Görkem Özcan is a young professional with multidisciplinary background in management and engineering. He currently works as Project Manager at Credit Suisse, based in Zürich. He holds a BSc in Electronics Engineering from Sabanci University and MSc in Management, Technology and Economics from ETH Zürich. During his masters studies he worked at SAP Research as an intern and thesis student, researching requirements engineering practices in research projects.

• Requirements Engineering in Research Projects: Food for Thought

Gareth is an experienced business analyst and product owner who has been working in the telecoms and other industries for longer than he’d like to be specific about. He has been an active member of IREB for some years and is a co-author and examiner within the RE@Agile working group. He lives and works in Germany having successfully escaped from a small, slightly uncooperative island.

• Splitting Requirements at Scale
• RE in Agile Projects: Survey Results
• RE in Agile Projects: a Survey
• How agile can Requirements Engineers really be?

Deepti works at the RnD Department of Siemens Corporate Technology, Bangalore. Her responsibilities include RE consulting, applied RE research, and delivering in-house RE and Scrum Trainings. Her research interests include handling requirements in agile development, and requirements visualization. Deepti has a Masters in Software Engineering from the University of Melbourne, and is an IREB-CPRE. She still enjoys writing neat, unambiguous requirements specifications in structured templates and striving to get stakeholders to read them.

• Survival Kit for the RE Guy

Luisa Mich is an Associate Professor of Computer Science at the University of Trento, Italy. Her research interests include requirements engineering, creativity and web strategies. She is an author of more than 150 papers.
 

• Requirements Elicitation (ReqElic) in My Company

Victoria Sakhnini is an adjunct lecturer at the Cheriton School of Computer Science at the University of Waterloo. Her research includes empirically validating the effectiveness of a new technique to enhance requirements-elicitation creativity and effectively teaching computer science principles.
 

• Requirements Elicitation (ReqElic) in My Company

Daniel M. Berry got his B.S. in Mathematics from Rensselaer Polytechnic Institute, Troy, New York, USA in 1969 and his Ph.D. in Computer Science from Brown University, Providence, Rhode Island, USA in 1974. He was on the faculty of the Computer Science Department at the University of California, Los Angeles, California, USA from 1972 until 1987. He was in the Computer Science Faculty at the Technion, Haifa, Israel from 1987 until 1999. From 1990 until 1994, he worked for half of each year at the Software Engineering Institute at Carnegie Mellon University, Pittsburgh, Pennsylvania, USA, where he was part of a group that built CMU's Master of Software Engineering program. During the 1998-1999 academic year, he visited the Computer Systems Group at the University of Waterloo in Waterloo, Ontario, Canada. In 1999, Berry moved to what is now the the Cheriton School of Computer Science at the University of Waterloo. Between 2008 and 2013, Berry held an Industrial Research Chair in Requirements Engineering sponsored by Scotia Bank and the National Science and Engineering Research Council of Canada (NSERC). Prof. Berry's current research interests are software engineering in general, and requirements engineering and electronic publishing in the specific.
 

• Requirements Elicitation (ReqElic) in My Company

Gareth is an experienced business analyst and product owner who has been working in the telecoms and other industries for longer than he’d like to be specific about. He has been an active member of IREB for some years and is a co-author and examiner within the RE@Agile working group. He lives and works in Germany having successfully escaped from a small, slightly uncooperative island.

• Splitting Requirements at Scale
• RE in Agile Projects: Survey Results
• RE in Agile Projects: a Survey
• How agile can Requirements Engineers really be?

Patrick Saint-Dizier, PhD, is a senior researcher in Computational Linguistics and Artificial Intelligence at CNRS, IRIT, Toulouse, France. He is specialized in discourse and semantic analysis. He has developed several national and European projects dedicated to logic programming, argumentation and technical text analysis. He is the author of several conference and journal articles and of 11 books. Besides foundational research, he has a long practice and experience of research and development activities. Contact: stdizier@irit.fr

• LELIE

Juyeon Kang has a PhD in Computational Linguistics (syntax and formal semantics) from the University Paris-Sorbonne. She is a R&D Engineer at Prometil (Toulouse) and associate researcher at IRIT-CNRS. She is specialized in argumentation mining and technical document authoring. She has been involved in a number of international projects. Her research results have been published in various international conferences and journals.

• LELIE

Joy Beatty is a VP at Seilevel, a professional services company whose mission is to define software that customers love to use. Joy implements new methodologies that improve the requirements process. Her team provides assessments, mentoring, training and consulting services for F1000 companies.

Joy is actively involved as a leader in the requirements community. She was a co-author of PMI’s Business Analysis for Practitioners: A Practice Guide, as well as being on the core team for the IIBA’s Business Analysis Body of Knowledge (BABOK) version 3. She is also a contributing author to “The Guide to Business Analysis” which “Includes the Standard for Business Analysis” by PMI. She co-authored Visual Models for Software Requirements with Anthony Chen and Software Requirements, 3rd Edition with Karl Wiegers.

• Making “agiLE” Work
• Project Value Delivered

Candase is a Product Manager at Seilevel. As a trainer and a practitioner, she helps ensure her clients’ software projects deliver the most return on investment, and helps define the problems their projects are trying to solve. She has provided training for business analysts in F300 companies, as well as assisting in the development of Seilevel training material. She also provided editorial contributions to both Visual Models for Software Requirements and Software Requirements, 3rd Edition.

• Making “agiLE” Work
• Project Value Delivered

Having finished her diploma in quantum optics Maria-Therese Teichmann couldn’t resist meeting the complex challenges of Information Technology. For fifteen years she has been working at Software Daten Service GmbH as a business analyst and quality manager in banking software. Her focus there are long term quality decisions, which nowadays are more and more difficult to argue against business interests. Besides the business job she loves to work at the University of Applied Sciences Technikum Wien, was part of a gender project and offers classes in software evolution, relational databases and Software Engineering topics.

• Gender Studies

Eva Gebetsroither works as a Senior Technical Translator in the localisation team of Software Daten Service GmbH. Apart from translations and terminology management she is responsible for language quality assurance. Within the framework of her field of activity there are numerous connections to Requirements Engineering. As an expert in the area of languages and communication she focuses on the role of natural language in Requirements Engineering.

• Gender Studies

After graduating in Communication Science with a focus on public relations and corporate communications in Salzburg and Shanghai, Corinna Unterfurtner finished the MBA in General Management with a focus on coaching, training and education. Corinna collected practical experience as a project manager at the University of Salzburg. Now she is responsible for project and requirements management, the training of new customers and support requests at an ERP business software for SME. Additionally she supports customers in process optimization and workflow design with the help of HELIUM V.

• Gender Studies

Alexandra Kreuzeder is the project manager of "ditact women's IT summer studies", that is part of the ICT&S Center of the University of Salzburg. She graduated at the University of Vienna in Sociology in 1997. Focusing on the processes of socialization, she started in 1998 a year-long research project concerning the gender socialization processes of girls and boys in kinder gardens in Copenhagen, Denmark. Returning to Salzburg in August 1999 she worked in the field of Internet Technology and was project manager of the ditact_women's IT summer university. From March 2011-November 2012 she took a time out to build up her own company "Salzburg Coaching" that offers communication and stress reduction training. Since last year she has shared the management of the ditact summer university with Carina Bachinger from the ICT&S Center.

• Gender Studies

Jens Schirpenbach has been working as a consultant in the area of Product Lifecycle management for more than 12 years focusing on operations transformation in the area of Engineering and Services. He worked as a solution architect and project manager for diverse projects, essentially in the automotive, aerospace and manufacturing industry. He managed a team for PLM at a major European consultancy. After eleven years in consulting he founded P&PM Solutions & Consulting.
He has a joint master degree in mechanical Engineering and business administration of the University of Darmstadt, Germany.

• Opportunities & Approaches

The International Requirements Engineering Board (IREB) e.V. has joined forces with the vision to create an international, professional basis for Requirements Engineering (RE) and to improve the knowledge in RE and its application, in order to give this discipline the importance and the orientation that corresponds to its added value for the industry.

The IREB is the developer and the holder of the CPRE (Certified Professional for Requirements Engineering) certification scheme, which stands for an elaborated three level certification concept.

Website: www.ireb.org

• Building the bridge

Cristina Palomares is a PhD student in the Software Engineering for Information Systems Research Group (GESSI) at the Universitat Politècnica de Catalunya (UPC). Her PhD thesis deals about the construction, use and evolution of software requirement patterns for the reuse of requirements knoledge.

She has published several papers and presented posters and demos in requirements engineering conferences like in IEEE International Requirements Engineering Conference (RE) and the International Working Conference on Requirements Engineering: Foundation for Software Quality (REFSQ). She is the coordinator of developers of the PABRE System for supporting requirements reuse.

• What is the Relevance of Requirements Engineering Research to Practitioners?
• Requirements Reuse

Dr. Carme Quer is associate professor in the Service and Information System Engineering department (ESSI) at the Universitat Politècnica de Catalunya (UPC). She is member of the Software Engineering for Information Systems Research Group (GESSI) at the UPC. Her main research lines are requirements engineering and software quality.

She has published several papers in requirements engineering conferences like in the IEEE International Requirements Engineering Conference (RE) and the International Working Conference on Requirements Engineering: Foundation for Software Quality (REFSQ). She was General Chair of the Workshop on Requirements Engineering (WER) held in 2008.

• What is the Relevance of Requirements Engineering Research to Practitioners?
• Requirements Reuse

Xavier Franch is Professor at the Universitat Politècnica de Barcelona (UPC-BarcelonaTech), Spain. He is Council Member and Full Member of the IREB association. He has published over 200 peer-reviewed papers in conferences and journals, many of them related to requirements engineering. He was Program Co-Chair of the RE’16 and REFSQ’11 conferences, and he belongs to the Editorial Board of the Requirements Engineering Journal (Springer) and Information Software and Technology (IST) journals, among others. He is coordinator of the Q-Rapids project and participates in the OpenReq project, both in the H2020 programme. He organizes workshops concerning requirements engineering for NLP4RE, CrowdRE, JIT-RE and others.

• What is the Relevance of Requirements Engineering Research to Practitioners?
• Requirements Reuse