Reference Models for IT Service Provision

This type of model is similar to Bernus’s “Abstract” (Bernus 1998) reference models or Loo’s “Generic Structures” (Loos et al. 1996). These are reference models that are at a level of abstraction that they require the addition of enterprise specific detail to produce the enterprise specific model. These models require that the user “fill-in-the-blanks” (Bernus 1998) or require 2 The term “derivation” is used to describe the process where by a reference model is transformed into an enterprise specific model. It is similar to “adaption” from GERAM (Bernus 1998) or “instantisation” from the CIMOSA modelling framework (René Gaches Year Unknown). Masters Thesis Chris Taylor QUT Page 31 mapping to certain specific semantic meanings before they can be used. This characteristic is related to the “Level of Abstraction” characteristic type. It is subtly different however, because it is drawn not from the level of abstraction of the model, but the difference between the level of abstraction in the reference model and the expected abstraction level of the Enterprise Specific Models. An “Abstract” model is specifically designed to provide a high level framework for the development of the enterprise specific model. 2.3.3 Characteristics from a Review of Reference Models Along with these previously defined characteristics a review of available reference models reveals there are other important aspects of reference models. As mentioned earlier this classification was designed in part to aid selection of reference models in real life projects. With this in mind, a brief examination of available reference models was conducted and several more characteristic types have been added to the scheme. These were Distribution, Ability to Edit, and Currency. For the purposes of classification in this thesis these new characteristic types combined with the previously mentioned are complete and necessary. As above each of the characteristic types are explained then characteristics are proposed and explained below. Distribution This characteristic type describes how the reference model is made available. The characteristics are public domain, proprietary available for sale, proprietary available through membership and proprietary not available. Some reference models are available through multiple sources, for example ITIL is a public domain reference model, but several third parties claim to have ITIL modelled in their proprietary languages. These third party supplied models are proprietary for sale. In this case a single source reference model may be categorised in several distribution characteristics. Public domain A public domain reference model is one that is made freely available to the public or pay only for the publishing costs. Masters Thesis Chris Taylor QUT Page 32 Proprietary not available This characteristic describes those reference models that are not available for the public in any form, often these are the intellectual property of commercial organisations such as consultancy firms who would see that information as their competitive advantage. Such models may become available to the clients of such organisations. An example of this is the IT Service Management reference model from HP. Proprietary available for sale These models are available for purchase from the developers or distributors. An example of such as developer is IDS-Scheer based in Germany. Proprietary available through membership These models are available after obtaining membership (usually for a fee) with an organisation, typically a body representing a particular industry or area. An example of this method of distribution is the SCOR reference model which is available to members of the Supply Chain Council. Ability to Edit Related to the tool support is whether the reference model is able to be edited or modified in its original form. Locked Locked models are not modifiable in there original form. This would include reference models that are supplied in hard-copy only, or media such as a locked adobe acrobat file. Open Open models are modifiable in their original form, assuming access to the appropriate tool is available. Currency Currency is an indication of the timeliness of the model content, and whether the content of the model is updated. Masters Thesis Chris Taylor QUT Page 33 Living Living models are reviewed and updated with a degree of regularity. This can be done through inputs from users of the models, surveys or other review mechanisms. Upgrading a reference models faces similar challenges to the design of new models (Design is addressed in Chapter 5). Static These reference models are those that were never updated, they are released once in a final version. Discontinued These models are those that were once living models but the review and update processes has been stopped. This is particularly evident in several of the OSI reference models or the TeleSPICE model which received many updates soon after its release, and has had no updates for several years. 2.3.4 Classification Summary Presented in Table 3 is the proposed classification scheme showing the characteristic types drawn from the academic literature as described in Table 1, and the new characteristic types drawn from a review of existing reference models. Masters Thesis Chris Taylor QUT Page 34 Characteristic Type Comb Characteristics View M Data/ Information Process/ Behaviour Function Organisational Language Formality 1 Natural Language Meta-Model Ontological Theory Level of Detail M Complete Intermediate Task Focus 1 Business Technical Application State 1 Common Practice Best Practice Functional Area 1 Function Specific Enterprise Inter-organisational Economic Activity (Industry) 1 Org. Specific EA Specific General Tool Support N Producer supplied Third party supplied Public Domain Extended Content N Implementation Run-Time Model Explanation Readiness for use 1 Single depiction Contains variants Abstract Distribution M Public Domain Proprietary not available Available for purchase Available through membership Ability to Edit 1 Locked Open Currency 1 Living Discontinued Static Table 3: Classification of Reference Models The column marked with “Comb” denotes the allowable combinations of the characteristics. “M”: Indicates that any combination may be possible, but at least one (i.e. 1,m) “N”: Indicates any combination may be possible (including none) (i.e. 0,m) “1”: The characteristics are mutually exclusive. (i.e. 1,1) These combinations are a guide only, as it could be argued for example that related models presented in languages of different formalities are separate reference models, or simply parts of the single reference model. Also characteristics of the model may change over time. Masters Thesis Chris Taylor QUT Page 35 This scheme simply suggests the relationship between the characteristics within a particular characteristic type to aid in the application of the classification framework. This scheme has been drawn from literature and derived through the author’s work and may not be exhaustive. 2.3.5 Example of Reference Model Classifications Supply Chain Operations Reference Model The Supply Chain Operations Reference Model (SCOR) has been developed by the Supply Chain Council, a non-profit industry organisation focused on supply chain issues. It contains descriptions of the processes of a typical supply chain, based mainly around manufacturing industries. It uses a series of arrows and boxes with specific naming methods and so falls into the MetaModel level of language formality, however there is no meta-model presented (only implied). The level of sophistication of the modelling technique is very low. The nominal focus is on the business process of an organisation, however the model is really only a functional model, with some dependencies on information and resources (i.e. inputs and outputs) shown, but no business rules for how or when the functions are executed. It attempts to highlight best practice. Due to the nature of its domain the model is an inter-organisational model, mapping the process through 5 organisations (from the suppliers’ supplier through to the customers’ customer) through a supply chain. Although it claims to be industry independent the model only makes sense in a manufacturing or distribution industry (i.e. not a service industry). More specifically, it is most applicable to high turn over manufacturing or engineering environments. The main advantage of this model is the identification and definition of supply chain performance metrics, giving the model extended “Run-time” content. The model contains process elements that can be plugged into the model, hence the model is of the “Contains Variants” Readiness for use type. Masters Thesis Chris Taylor QUT Page 36 The model is accessible through membership to the supply chain council, and comes in two forms, either a document, or in a dedicated tool, the different versions respectively locked and open. The model at this stage is living and the description taken from Version 5.0 . From the description above the following classification Table 4 is derived. Characteristic Type Characteristics View Data/ Information Process/ Behaviour Function Organisational Language Formality Natural Language Meta-Model Ontological Theory Level of Detail Complete Intermediate Task Focus Business Technical Application State Common Practice Best Practice Functional Area Function Specific Enterprise Inter-organisational Economic Activity (Industry) Org. Specific EA Specific General Tool Support Producer supplied Third party supplied Public Domain Extended Content Implementation Run-Time Model Explanation Readiness for use Single depiction Contains variants Abstract Distribution Public Domain Proprietary not available Available for purchase Available through membership Ability to Edit Locked Open Currency Living Discontinued Static Table 4: Example reference model classification of SCOR This provides an example of how the characteristics are derived from an examination of the model. The same straightforward method of assigning characteristics was applied throughout the rest of the thesis, and will not be explained again. Masters Thesis Chris Taylor QUT Page 37 2.4 Typical Applications of Reference Models There have been many uses touted for reference models. To provide a structure for discussion this section is broken into the ‘focus’ characteristic as described in the previous section. The focus characteristic categorises what the reference model is describing, and hence can a framework for analysing how the reference models are used. Technical Reference Models One extensive use of reference models has been in the area of information technology. Technical reference models generally provide a conceptual framework for development of technical systems. Zwegers states that reference models “serve as a point of departure for the design of a large number of systems in a specific application area”. (Zwegers 1998). Examples of technical reference models include many from the ISO, including ISO/IEC 11072:1992 Information technology outlining computer graphics standards or the ISO/IEC 14662:1997 Information technology Open-EDI reference model which describes the interfaces and standards of Electronic Data Interchange. Others include the Workflow Reference Model (Hollingsworth 1995) which defines the standard interfaces for a workflow management system. One of the most commonly referenced technical models is the ISO-OSI reference model. It is provides a framework for the development of communication systems and the seven layers depict the different elements that make transform the communication from the human interaction to the physical transmission and back up again to the human interface. It is interesting to note that this is not the backbone of the most commonly used electronic communication – the Internet (which uses TCP/IP). Despite it not actually being widely used the reference model’s ability to be able to effectively and simply define a complex situation has made it popular. This highlights one of the uses of a reference model, to display complex ideas in such a way that it is easily understood and conceptualised. Masters Thesis Chris Taylor QUT Page 38 What these reference models have in common is that they attempt to provide an accepted conceptual or technical standard. This standard ensures that the products developed under the standard can fit neatly into their respective roles. They act as input for requirements engineering ensuring that vendors’ products conform to the relevant standards. Application Reference Models The use of reference models is not only confined to the technical side of IT. Recently several application reference models have been proposed that deal with how IT systems can be used, particularly business process models of enterprise systems (e.g. SAP R/3, Siebel or Baan Reference Models). One of the major aims of application reference models is to aid with the configuration and implementations of the applications they describe. They help to align the application to the business requirements and can be used to describe the supported business processes, data structures, architectures or configuration alternatives of the applications. Typically the process reference models of application models describe the human-application interface of the application. Application reference models also include models of business or human interactions which are used to design or configure IT systems. Examples of this type of reference model can also be found in the area of web services and e-market places. Business Reference Models Business reference models are mainly focused on describing business concepts, such as business processes, structures, financial arrangements etc. An example is the Process Classification Framework (Anonymous) which provides a generic functional decomposition for a commercial operation, or the teleSPICE reference model (Emam et al. 1998; Anonymous 2002) which, in part, describes the processes one should complete when developing software. Business Reference Models are useful to: Masters Thesis Chris Taylor QUT Page 39 • Communicate “best/common/accepted” practices • Structure a performance measurement framework • Encourage reuse in multiple instances and consistency in model efforts • Provide guidance or a template for modelling efforts • Facilitate the classification, evolution and comparability of models by creating a standard terminology They provide assistance in • Business Process Management (BPM) • Knowledge Management • Process Benchmarking and Performance Measurement (Anonymous 1998; Bernus et al. 1998; Curran et al. 1998; Lowe and Webby 1999; Misic and Zhao 2000; Kaplic and Bernus 2001; Anonymous Year Unknown) As described in Chapter 1, of particular interesting in this research is business process modelling and business process reference models. The next sections look into both of these areas. 2.5 Business Process Modelling A conceptual model is a simplified depiction of an extraction of reality (Curtis et al. 1992). The information presented in the model is, in the model creators’ opinion, all the relevant information needed to fulfil the purpose of the model (Lindland et al. 1994; Davis 2001). Ideally the model should contain only the minimum required in order to fulfil its purpose and hence “excludes much of the world’s infinite detail” (Curtis et al. 1992). This is done in two steps, firstly minimising the scope of the model, focusing on only the relevant objects, and secondly by depicting this defined scope in a minimalistic manner. By doing this it would comply with Albert Einstein’s suggestion to “make everything as Masters Thesis Chris Taylor QUT Page 40 simple as possible, but not simpler” (exact source unknown). Modelling in one form or another has taken place since the first caveman drew on the wall. Several formal modelling techniques were developed with the introduction of IT, as precise definitions are needed when working in the field. Data modelling was one example that many organisations used. In the 1990’s many organisations implemented large and complex enterprise systems, including Enterprise Resource Planning packages (ERP). The traditional focus on modelling data flows and transformations was not sufficient to capture the increased use of IT beyond data processing into areas of communications and co-ordination (Curtis et al. 1992). At the same time, popularised by Hammer in 1990 (Hammer 1990), the change from Taylor’s (Taylor 1911) scientific management principals to the process perspective marked a dramatic shift in business management. This deficiency in modelling techniques and the contemporary popular focus on BPR increased the need for a process modelling. A process (used often synonymously with business process) can be defined as: “a self contained, temporal and logical order of those activities, that are executed for the transformation of a business object with the goal of accomplishing a given task” (Green and Rosemann 2000). “the definition of the tasks and the sequence of those tasks necessary to deliver a business function” (Davis 2001) “a set of partially ordered steps intended to reach a goal” Humphrey and Feiler (1992) in (Curtis et al. 1992), or “a structured, measured set of activities designed to produce a specified output” (Davenport 1993). Hence process modelling (or business process modelling, BP Modelling) can be defined as: “the capture, documentation and analysis of [business processes]” (Davis 2001 p2), or Masters Thesis Chris Taylor QUT Page 41 “an abstract description of an actual or proposed process that represents selected process elements that are considered important to the purpose of the model” (Curtis et al. 1992 p.76). The working definition for this thesis is: Business process modelling is the activity of capturing and analysing the important aspects of a business process. In the early stages of process modelling the focus was on the use of models to describe and implement IT based solutions. Business process modelling differs significantly from the more traditional modelling techniques used in the field of IT because “many of the phenomena modelled must be enacted by a human rather that a machine” (Curtis et al. 1992 p77). Today, BP Modelling is seen as part of Enterprise Modelling, and related upper-CASE (computer aided software engineering) tools allow the integration of process design at a conceptual level with the coding into Enterprise Systems, for the enactment of these processes, and ultimately the monitoring of these processes (van der Aalst and Kumar 2001). Even though some models produced included both semi-manual and IT executed steps the main emphasis was on the IT system, sometimes excluding the solely manual steps. As BP Modelling matured the advantages of using it in areas outside the IT domain became apparent. Today BP Modelling has been used to map the entire process, as originally proposed by Hammer, regardless of whom or what executes the function. Various uses for BP Modelling have been summarised in Table 5 adapted from (Rosemann et al. 2003). Improvement of internal business processes Improvement of collaborative business processes Software development Design of Enterprise Architecture Business process documentation Change Management Workflow management Training Masters Thesis Chris Taylor QUT Page 42 Table 5: Examples of uses for Business Process Modelling While parts of the remainder of this thesis may be applicable to reference models in general, the term reference model is used to indicate business process reference models in particular from now on. 2.6 Applying Business Process Reference Models This section summaries and extends the literature with respect to the use of business process reference models, as highlighted in Figure 3. In particular it focuses on using business process reference models in Business Process Re-engineering (BPR) projects, one of the major uses for business process reference models. The section answers the third research question: “How can business process reference models be used for process management?” Figure 3: Chapter 2.6 in relation to the Reference Model Lifecycle Very few published works have mentioned how to apply a reference model. Two exceptions, however, are brief mentions in Schlagheck and Scheer. Schlagheck 2000 (in Fettke and Loos 2003) details four steps in the process of applying a reference model: Design Reference Model