Principles of Data Management

Facilitating information sharing

Keith Gordon

• Publisher: BCS, The Chartered Institute for IT
• Year: 2013
• eBook ISBN: 9781780171869
• Edition: 2
• Topic: Computer Science
• Subtopic: Information Management
• Index: Computer Science

Data is a valuable corporate asset and its effective management can be vital to an organisation's success. This professional guide covers all the key areas of data management, including database development and corporate data modelling. It is business-focused, providing the knowledge and techniques required to successfully implement the data management function. This new edition covers web technology and its relation to databases and includes material on the management of master data.

PART 1
PRELIMINARIES

In this part we describe the importance of data to the enterprise, introduce the concept of database design and consider the roles and responsibilities of data management within an enterprise. This part has three chapters.

Chapter 1 – Data and the Enterprise – introduces the idea that information is a key business resource. It starts by exploring the relationship between information and data. We then move on to a discussion of the importance of the quality of the data that underlies the information. If the quality of data is important, what are the common problems with data? Why must we take an enterprise-wide view of data? The chapter concludes by highlighting that the management of data is a business issue and not a technical issue.

Chapter 2 – Database Development – is a long, largely technical chapter that provides an explanation of how the databases at the heart of all information systems are designed. It introduces the concepts of database architecture and then provides examples of two analysis techniques – conceptual data modelling and relational data analysis – and how these lead to a physical database design.

Chapter 3 – What is Data Management? – first considers the problems encountered without data management, then introduces the scope of the responsibilities of data management. We then look at the three separate roles within data management – data administration, database administration and repository administration. We end this chapter by summarising the benefits of data management.

1 DATA AND THE ENTERPRISE

This chapter introduces the concepts of information and data and discusses why they are important business resources within the enterprise. We start to discuss some of the problems caused by data which is of poor quality or inconsistent, or both.

INFORMATION IS A KEY BUSINESS RESOURCE

When asked to identify the key resources in any business, most business people will readily name money, people, buildings and equipment. This is because these are the resources that senior business managers spend most time managing. This means that in most businesses there is a clear investment by the business in the management of these resources. The fact that these resources are easy to manage and that the management processes applied to these resources can be readily understood by the layman means that it is seen to be worthwhile investing in their management. It is usually easy to assess how much the business spends on managing these resources and the return that is expected from that investment.

But there is a key resource missing from that list. That missing resource is ‘information’. Without information, the business cannot function. Indeed, it could be said that the only resource that is readily available to senior management is information. All important decisions made within an enterprise are based on the information that is available to the managers.

Despite its importance, most business people do not recognise information as a key business resource. Because of its association with technology (with ‘information technology’ having become in effect one word, generally with more emphasis on the ‘technology’ than on the ‘information’), information is seen as something mystical that is managed on behalf of the business by the specialist information technology or information systems department. The management of information is seen, therefore, as something requiring special skills beyond the grasp of the layman. It is very difficult to determine how much the business spends on managing information or, indeed, the return it can expect from that expenditure.

Information is a business resource that is used in every aspect of a business: it supports the day-to-day operational tasks and activities; it enables the routine administration and management of the business; and it supports strategic decision making and future planning.

For a supermarket chain the operational tasks and activities include the processing of customers’ purchases through the electronic point-of-sale system and the ordering of goods from suppliers; for a high street bank they include the handling of customers’ cash and cheques by the cashiers, the processing of transactions through ATMs and the assessment of the credit status of a customer who is requesting a loan; for an online book ‘store’ they include the collection of customers’ orders, the selection and dispatch of the books and the production of a customer profile enabling the ‘store’ to make recommendations to customers as they log on to the website.

For all types of business, information in various forms is routinely used by managers to monitor the efficiency and effectiveness of the business. Some of this information comes in the form of standard reports. Other information may come to the managers as a result of their ad hoc questions, perhaps directed to their subordinates but, increasingly, directed to the information systems that support the business.

All businesses need to plan for their future and take high-level strategic decisions. In some cases the consequence of making an incorrect strategic decision could be the ultimate collapse of the business. To carry out this future planning and strategic decision making, the senior management of the business relies on information about the historic performance of the business, the projected future performance of the business (and this, to a large extent, will be based on an extrapolation of the historic information into the future), its customers’ present and future needs and the performance of its competitors. Information relating to the external environment, particularly the economy, is also important. For a supermarket chain these decisions may include whether to diversify into, say, clothing; for a high street bank they may include the closure of a large number of branches; and for an online book ‘store’ whether to open new operations overseas.

Information is important, therefore, at every level in the business. It is important that the information is managed and presented in a consistent, accurate, timely and easily understood way.

THE RELATIONSHIP BETWEEN INFORMATION AND DATA

Wisdom, knowledge, information and data are all closely related through being on the same continuum – from wisdom, to knowledge, then to information and, finally, to data. This book is about managing data to provide useful information so we will concentrate on the relationship between information and data.

An often-heard definition of information is that it is ‘data placed in context’. This implies that some information is the result of the translation of some data using some processing activity, and some communication protocol, into an agreed format that is identifiable to the user. In other words, if data has some meaning attributed to it, it becomes information.

For example, what do the figures ‘190267’ represent? Presented as ‘19/02/67’ it would probably make sense to assume that they represent a date. Presented on a screen with other details of an employee of a company, such as name and address, in a field that is labelled ‘Date of Birth’ the meaning becomes obvious. Similarly, presented as ‘190267 metres’, it immediately becomes obvious that this is a long distance between two places, but for this to really make sense the start point and the end point have to be specified as well as, perhaps, a number of intermediate points specifying the route.

While these examples demonstrate the relationship between data and information, they do not provide a clear definition of either data or information.

There are many definitions of data available in dictionaries and textbooks, but in essence most of these definitions basically say that data is ‘facts, events, transactions and similar that have been recorded’. Furthermore, as I pointed out earlier, the definition of information is usually based on this definition of data. Information is seen as data in context or data that has been processed and communicated so that it can be used by its recipient.

The idea that data is a set of recorded facts is found in many books on computing. However, this concept of data as recorded facts is used beyond the computing and information systems communities. It is, for example, also the concept used by statisticians. Indeed, the definition of data given in Webster’s 1828 Dictionary – published well before the introduction of computers – is ‘things given, or admitted; quantities, principles or facts given, known, or admitted, by which to find things or results unknown’.

However, developing our definitions by looking at data first appears to be starting at the wrong point. It is information that is important to the business and it is there that our definitions, and our discussion about the relationship between information and data, should really begin.

We start by considering the everyday usage of information – something communicated to a person – and with that we can find a definition of data that is relevant to the theme of this book. That definition is found in ISO/IEC 2382-1, 1993 (Information Technology – Vocabulary – Part 1: Fundamental terms) and it states that data is ‘a re-interpretable representation of information in a formalised manner suitable for communication, interpretation or processing’. There is a note attached to this definition in the ISO/IEC standard which states that data can be processed by human or automatic means; so this definition covers all forms of data but, importantly, includes data held in information systems used to support the activities of an organisation at all levels: operational, managerial and strategic.

Figure 1.1 provides an overview of the relationship between data and information in the context of a computerised information system. The user of the system extracts the required information from their overall knowledge and inputs the information into the system. As it enters the system it is converted into data so that it can be stored and processed. When another system user requires that information, the data is interpreted – that is, it has meaning applied to it – so that it can be of use to the user.

For most of this book we consider data stored in a database. This is often called ‘structured data’. However, it must be understood that a considerable proportion of an organisation’s information may be held in information systems as ‘unstructured data’ – in word-processed docume...

Table of contents

• Front Cover
• Half Title Page
• Title Page
• Copyright
• Epigraph
• Contents
• List of figures and tables
• Author
• Foreword to the first edition
• Glossary
• Preface
• Introduction
• PART 1: PRELIMINARIES
• PART 2: DATA ADMINISTRATION
• PART 3: DATABASE AND REPOSITORY ADMINISTRATION
• PART 4: THE DATA MANAGEMENT ENVIRONMENT
• APPENDICES
• Back Cover