MODELLING BUSINESS INFORMATION Gordon Keith Entity relationship and class modelling for business analysts MODELLING Keith Gordon It is almost universally accepted that requirements documents A thoughtful, well- for new or enhanced IT systems by business analysts should BUSINESS include a ‘data model’ to represent the information that has to done text on how to do be handled by the system. high-quality business Starting from first principles, this book will help business analytical data modelling. INFORMATION analysts to develop the skills required to construct data models David Hay, Essential Strategies through comprehensive explanations of entity relationship and International, CEO class modelling, in line with the BCS Data Analysis syllabus. In addition to covering the topics in the syllabus, the book also Entity relationship and class includes significant extra information of interest including an A terrific contribution to MODELLING BUSINESS INFORMATION overview of other modelling notations, information model the field. quality, and taking a requirement model into database design. modelling for business analysts Alec Sharp, Senior Consultant, • Explains why business analysts should model information Clariteq • Covers both entity relationship and class modelling in tandem from the basics Provides an excellent Keith Gordon • Aligned with the BCS Data Analysis syllabus • Goes beyond the syllabus to include several wider topics grounding in the full of interest range of topics related to ABOUT THE AUTHOR information modelling. Keith Gordon is an independent consultant and lecturer Matthew West, Information specialising in data management and business analysis. Junction, Director He has spent over 50 years in technical, education and training environments as an engineer, computer consultant, data manager, business analyst and education and training manager. You might also be interested in: Computing; IT Cover photo: iStock © nuwatphoto ISBN 978-1-78017-353-5 Ebooks available Paperback available 9 781780 173535 As the roles of Data and Business Analysts become more intertwined, this book is timely in its publication. Businesses often fail to recognise information is a key resource and are confused by how it is presented or overwhelmed its complexity during use. Keith brings to the forefront of the readers mind the importance of communicating and analysing the relationship between Business, Information, Systems and Data, and the value in developing models cooperatively, gaining ‘consensus, not perfection’ from stakeholders. Simple everyday examples and analogies to support the readers under- standing and make the subject more relatable are used. I enjoyed reading the book and completing the exercises. An excellent learning aid for Analysts who are new to modelling or need reminding of good practice. Katie Walsh, Business Analyst and Mentor Anyone interested in a thoughtful, well-done text on how to do high-quality business analytical data modelling should definitely proceed with this book. David Hay, Essential Strategies International, CEO Modelling Business Information provides an introduction to data modelling, to the nomen- clature used by common modelling techniques, and to techniques for representing common patterns. This is a useful book for business analysts who are creating the information model as well as for business and IT users who need to understand a data model. Keith W. Hare, JCC Consulting, Inc., Senior Consultant Keith Gordon’s wonderfully compact yet thorough introduction to business-friendly information modelling is a terrific contribution to the field. Globally, there’s a surge of interest in data modelling as a powerful tool for improving communication, especially with professionals who used to think business-oriented entity relationship modelling didn’t need to be in their tool kits. Business analysts, Agile developers, data scientists, big data specialists, and other professionals will all benefit from Keith’s work. Alec Sharp, Senior Consultant, Clariteq Modelling Business Information by Keith Gordon, is aimed at those who are new to busi- ness analysis or information modelling. Keith draws on a wealth of experience in infor- mation management, both as a practitioner, and as a lecturer with the Open University in his writing. The first six chapters provide an accessible and clear foundation in the topic cov- ering the reasons for developing information models, the basic elements of entity- relationship diagrams, how to develop an information model from basic information requirements, and finally how to normalise existing data. I particularly like that it uses two graphical notations, the Barker-Ellis notation, noted for its readability, and the ubiquitous Unified Modelling Language notation, which helps to demonstrate that there are different notations that entity-relationship models can be developed in. This first part of the book also takes care to cover the syllabus for the Data Analysis certificate that is part of the scheme for the BCS Advanced International Diploma in Business Analysis. The second part of the book covers a range of more advanced topics from naming con- ventions and yet more entity-relationship model notations, to considerations of quality in information models, corporate data models, modelling for business intelligence applica- tions, and finally goes on to look at data and database topics including an overview of SQL, and moving to database design and optimisation. Overall, the book provides an excellent grounding in the full range of topics related to information modelling. Matthew West, Director, Information Junction MODELLING BUSINESS INFORMATION BCS, THE CHARTERED INSTITUTE FOR IT BCS, The Chartered Institute for IT, champions the global IT profession and the interests of individuals engaged in that profession for the benefit of all. We promote wider social and economic progress through the advancement of information technology science and practice. We bring together industry, academics, practitioners and government to share knowledge, promote new thinking, inform the design of new curricula, shape public policy and inform the public. Our vision is to be a world-class organisation for IT. Our 75,000-strong membership includes practitioners, businesses, academics and students in the UK and internationally. We deliver a range of professional development tools for practitioners and employees. A leading IT qualification body, we offer a range of widely recognised qualifications. Further Information BCS, The Chartered Institute for IT, First Floor, Block D, North Star House, North Star Avenue, Swindon, SN2 1FA, UK. T +44 (0) 1793 417 424 F +44 (0) 1793 417 444 www.bcs.org/contact http://shop.bcs.org/ MODELLING BUSINESS INFORMATION Entity relationship and class modelling for business analysts Keith Gordon © 2017 BCS Learning & Development Ltd The right of Keith Gordon to be identified as author of this work has been asserted by him in accordance with sections 77 and 78 of the Copyright, Designs and Patents Act 1988. All rights reserved. Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted by the Copyright Designs and Patents Act 1988, no part of this publication may be reproduced, stored or transmitted in any form or by any means, except with the prior permission in writing of the publisher, or in the case of reprographic reproduction, in accordance with the terms of the licences issued by the Copyright Licensing Agency. Enquiries for permission to reproduce material outside those terms should be directed to the publisher. All trademarks, registered names etc. acknowledged in this publication are the property of their respective owners. BCS and the BCS logo are the registered trademarks of the British Computer Society, charity number 292786 (BCS). Published by BCS Learning & Development Ltd, a wholly owned subsidiary of BCS, The Chartered Institute for IT, First Floor, Block D, North Star House, North Star Avenue, Swindon, SN2 1FA, UK. www.bcs.org Paperback ISBN: 9781780173535 PDF ISBN-13: 9781780173542 EPUB ISBN-13: 9781780173559 Kindle ISBN-13: 9781780173566 British Cataloguing in Publication Data. A CIP catalogue record for this book is available at the British Library. Disclaimer: The views expressed in this book are those of the authors and do not necessarily reflect the views of the Institute or BCS Learning & Development Ltd except where explicitly stated as such. Although every care has been taken by the authors and BCS Learning & Development Ltd in the preparation of the publication, no warranty is given by the authors or BCS Learning & Development Ltd as publisher as to the accuracy or com- pleteness of the information contained within it and neither the authors nor BCS Learning & Development Ltd shall be responsible or liable for any loss or damage whatsoever arising by virtue of such information or any instructions or advice contained within this publication or by any of the aforementioned. Typeset by Lapiz Digital Services, Chennai, India. vi CONTENTS List of figures and tables x About the Author xiii Foreword xv Acknowledgements xviii Glossary xix Introduction xxv PART 1 THE BASICS 1 1. WHY BUSINESS ANALYSTS SHOULD MODEL INFORMATION 3 What is business analysis? 3 Information and data 5 The importance for a business analyst of understanding information needs 6 The role of models in business analysis 7 Data models and data 10 Entity relationship modelling 11 Class modelling 12 Use of data models in business