What Is Configuration Management? - …

1 1 Part IWhat Is Configuration Management? Configuration, to form from or after, derives from the Latin com-, meaning with or together, and figurare, to form. It also means a relative arrangement of partsor elements. Configuration management therefore refers to managing a relativearrangement of parts or elements. It s as simple as management , as we know it today, started in the late 1960s. In the1970s, the American government developed a number of military standards, whichincluded configuration management . Later, especially in the 1990s, many other stan-dards and publications discussing configuration management have the last few years, the growing understanding of software development as acollection of interrelated processes has influenced work on configuration manage-ment.

2 This means that configuration management is now also considered from a pro-cess point of 1 Definition of Configuration management Used in This BookThere are many definitions of configuration management and many opinions on whatit really is. This chapter describes the definition on which this book is based. In short:Configuration management is unique identification, controlled storage, changecontrol, and status reporting of selected intermediate work products, productcomponents, and products during the life of a 1 1 shows the activity areas included in the definition of configurationmanagement used in this book. It also shows their relations to each other, to com-mon data, and to elements outside the configuration management process you work professionally with configuration management (as with any-thing else) it s important to have the fundamental concepts in place.

3 If all else fails,you can go back and seek a solution of configuration management used in various standards are coveredin Chapter 3, and definitions of configuration management used in various maturitymodels can be found in Chapter 2. The definitions in these standards and maturitymodels are similar to a large extent. However, they re expressed in slightly differentwords and with different divisions between the detailed activities that constitute con-figuration management . It s perfectly okay for a company to use its own definition ofconfiguration management , but it s a good idea to investigate how that definitionmaps to the definition used in this book and other relevant definitions, to make sureno activity has been left 1 Definition of Configuration management Used in This CONFIGURATION management ACTIVITIESThe view on configuration management in this book is process oriented.

4 Therefore, thedefinition includes activity areas, which can be described in terms of process descrip-tions. The activity areas described in detail in the following paragraphs are identifica-tion, storage, change control, and status management has many interactions with other development andsupport processes. Figure 1 1 illustrates the production and usage activity areas viatheir respective requestChange dataEventregistrationMetadataMetadataMet adataReportsProduction(dynamic)Storage(c ontrolled)ChangecontrolIdentificationNee dfrom planStatus ReportingUsage(static)ConfigurationitemC onfigurationitemFigure 1 1 Overview of Configuration management Configuration management Activities5 MetadataAll the activity areas in configuration management share metadata for items placedunder configuration management .

5 Metadata is a database concept that means dataabout the data stored in the database. So metadata in this context describes the con-figuration items. Metadata for a configuration item may include its name, the nameof the person who produced the item, the production date, and references to otherrelated configuration items. Figure 1 1 shows a logical separation of metadata, eventhough this data is often stored physically at the same location (in the same database)as the items in controlled control uses metadata for example, the trace information for a configu-ration item for which a change is suggested. Change control does not in itself con-tribute to metadata, because information produced during change control will bepresent only if a configuration item is affected by a suggested change.

6 A configura-tion item can exist without change control information, but it can t exist management Is Cyclic or Is It?In everyday language, configuration item is often used to refer to an item, which isthen said to be produced in several versions. This is not strictly correct, but it s accept-able as long as the reference is clearly understood by all involved. In fact, each newversion of a configuration item is a new configuration item in its own can be illustrated by an analogy to an object-oriented approach. The con-figuration item may be seen as a class and the versions as instantiations of the class,as shown in Figure 1 2. Version chains of configuration items that is, versions 1, 2,3, and so on may be formed by indicating which configuration item a given config-uration item is derived from or based management activities may be viewed as cyclic for each item classplaced under configuration management .

7 This means that a configuration item classcontinuously goes through the mill. The first cycle is initiated by a (planned) needfor a configuration item, and later the driving force is a change request (and onlythis!). This is illustrated in Figure 1 each cycle, a configuration item will be identified, produced, stored, andreleased for usage. Event registrations will occur as a consequence of experiencegained during usage. These will lead to change control and the creation of changerequests, which will lead to identification, and so on, of a new version of the original6 Chapter 1 Definition of Configuration management Used in This Bookconfiguration item. Items placed under configuration management must never bechanged, but new versions may be items that are different versions of the same original item areobviously strongly related, but each one is an individual item, which will be identifiedand may be extracted and used independently.

8 This is one of the main points of con-figuration management : to be able to revert to an earlier version of an item Assurance ProcessConfiguration management interacts with quality assurance, as illustrated by theitem approval process that accompanies a configuration item from production tostorage. The item approval, which may be a written quality record or verbal, is aUser requirement specification requirement specification requirement specification item instantiationsConfiguration item classUser requirement specificationFigure 1 2 Configuration Item Class and InstantiationsCSV. 1V. 2V. 3 IPUCSV. 1V. 2 PUIC hange controlStorageV. 1 ProductionUsageIdentificationFigure 1 3 The Life of a Configuration Item Identification7product of quality assurance. Some see it as a product of configuration management ,but it s actually the gateway from production to configuration management , pro-vided by quality is included in some definitions of configuration management .

9 An auditensures that the product the configuration item released for use fulfills the require-ments and is complete as delivered. This includes configuration management infor-mation, so that everything required is delivered in the expected versions and that thehistory of each item can be thoroughly accounted for. This activity area is not consid-ered part of configuration management in this book. It s viewed as an activity areaunder general quality assurance, which partly concerns the products and partly theprocesses, rather than a configuration management activity may be a controversial point of view, but the idea of audits is a legacy fromthe Department of Defense origin of configuration management . Today there is amuch broader understanding in the software industry of the importance of qualityassurance and, therefore, also of configuration uses configuration information extensively in the form of status reports,but it also uses quality assurance techniques and methods, such as reviewing and practice, people involved in configuration management also carry out the , the audit will be referred to elsewhere in this IDENTIFICATIONThe purpose of the identification activity area is to determine the metadata for a con-figuration item to uniquely identify it and specify its relations to the outside worldand other configuration is one of the cornerstones of configuration management , as it simpossible to control something whose identity you don t know.

10 If the tables in a res-taurant have no numbers to which orders can be traced, the waiter will have diffi-culty matching the dishes to the proper guests. Perhaps this will come off all right ifyou have three or four tables, but definitely not if you have more than 20 and theguests keep coming and going all evening and the waiter who serves the food is notthe one who received the order. To be sure everything is under control, the waitersand orders need to be uniquely identified as well. Figure 1 4 shows how identifica-tion is influenced by its 1 Definition of Configuration management Used in This BookInputsTwo incidents may initiate the identification process: The first time an item is to be placed under configuration management , identifi-cation starts with a need defined in the plans.