2.4 Enterprise Architecture Frameworks
2.4.3 Reflection on EAFs
An examination of the twelve frameworks reveals that all have certain strengths and weaknesses. The comparative analysis of strengths and weaknesses for each framework are presented in Table 6.
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TABLE 6: STRENGTHS AND WEAKNESSES OF ENTERPRISE ARCHITECTURE FRAMEWORKSFramework Strengths Weaknesses
Zachman - Systematic and layered
taxonomy
- Standard methodology, which can be used as reference by other frameworks
- Other systems can map to this methodology and use it as a reference model
- Used by private and public sector
- Simple, logical model which uses non-technical terminology - Provides good abstraction
views
- Does not have a defined
methodology or implementation process
- Can be used for reference - Over-emphasis on Information
Technology
- No emphasis on "How" to use it - Not suitable for complex multi-
enterprise contexts - Needs to depend on other
methodologies
- Does not provide clear direction on security
TOGAF - Greater usability
- Fully described open methodology (Architectural Design Methodology) - Hierarchical steps
- Linked to business drivers - Focuses more on holistic
enterprise change - Output is consistent
- Flexible step-by-step process to create a new architecture
- Excessively IT-centric
- Little emphasis on people issues - Does not emphasise non-IT-
based knowledge
- Limited description of business architecture
- Over-emphasis on low-level technology architecture
EA3 Cube - Provides good abstraction
- Layered
- Understands large, complex enterprises
- Components in the cube ideally suit all lines of business
- Business and IT focus - Best practices, tools and
flexibility (Hawk, 2008)
- Collection of artefacts based on other frameworks
- Does not provide strong direction on security - Does not have explicit
implementation methodology
Archimate - Open framework
- Non-proprietary - Process oriented
- Consistent and integrated modelling of IT and process - Integration with TOGAF
- No explicit methodology - More of an enterprise
architecture language than a framework
- IT centric
- No clear semantics behind the framework
- No reference to people or process except in IT context - Does not consider non-IT-based
knowledge
ARIS - Strongly process aware
- Useful for product development - Process simulation capability
- Proprietary model and
integration is supported only by specific ARIS tools
- Based on EPC modelling language
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TABLE 6: STRENGTHS AND WEAKNESSES OF ENTERPRISE ARCHITECTURE FRAMEWORKS(CONTINUE)Framework Strengths Weaknesses
DoDAF - Guarantees output and process
uniformity
- Documentation of data for assessment
- Requirements and architecture elements are universal
- Does not have unique
architecture development style - Does not have specialised
analysis techniques
- Very limited guidance quality attributes (Odongo et al., 2012) - No business aspects focus
FEAF - Systematic structure of inter-
related models - Fully described open
methodology
- Strongly business focus - Hierarchical
- Exclusively IT-centric - Does not have reference to
process and people - Does not recognise non-IT-
based knowledge - Ideal for public sector
enterprises and not business enterprises
- Its implementation has a tendency to be in favour of bureaucracy
Gartner - Practical framework
- Business focus - Not a complete EA methodology
- Does not have a step-by-step process to create a new
architecture and will not support implementation
- Not widely adopted
BMM/ EBMM
- Strong business focus (business plan, investment case, Return On Investment)
- Framework components ideally suit all lines of business
- Supports change management by tracking the semantics among the concepts
- The abstract concepts can be disadvantageous as they require more work to specify artefacts - Business focus, integration with
MDA technical standards can offer a fully socio-technical implementation
CIMOSA - Covers all important aspects for
process modelling (Zuesongdham, 2007) - IT and business focus
- Flexible (Zuesongdham, 2007)
- Manufacturing industry focus - Very complicated
- No reference models to design the system (Zuesongdham, 2007)
GERAM - Technical focus
- Offers clear guidance on the different aspects of functional, structural and contextual alignment (Magoulas et al., 2012)
- Lacks a complete
implementation methodology - Does not have strong business
focus
- Does not include time-based progression
The Zachman Framework and TOGAF are considered to be methodologies that are also described as enterprise architectural frameworks. Sessions (2007) argues that the Zachman methodology acts like a taxonomy (study of the principles of scientific classification) and not a framework, as a framework is a structure that supports a system (Sessions, 2007). However, the Zachman Framework is a straightforward framework and very popular among
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organisations (IDS Scheer, 2006). Some literature also argues that TOGAF does not compete with established architecture frameworks (IDS Scheer, 2006).DoDAF does not possess any unique characteristics of an ideal architecture model (Odongo et al., 2012), which makes it an advanced framework, and users need experience in how to compose and select the aspects and views and link them together. The EA3 Cube is considered to be an excellent EA Methodology reference as it embodies EA best practices. It is flexible and can be tailored to meet the requirements of any organisation (Hawk, 2008). Both Zachman and the EA3 cube have more layers and recommended artefacts with a comprehensive taxonomy than DoDAF 1.0.
FEAF is a good methodology as it combines the Zachman taxonomy and the TOGAF architectural process (Sessions, 2007). The main concern about FEAF is that it was created for the public sector and therefore may not be suitable for the private sector and medium- sized enterprises. However, it is an ideal reference model. Like TOGAF, FEAF is IT centric knowledge. However better versions are being developed which focuses on ‘human capital’ and ‘other fixed assets’.
The Gartner Architecture model is a ‘practice’ and not a taxonomy like Zachman, a process focus like TOGAF or a complete methodology like FEAF (Sessions, 2007). Gartner can be considered a good framework like Zachman in terms of driving IT and business value. Unlike Gartner and EA3, GERAM is based on the requirements of IT rather than on business objectives. However, GERAM, like TOGAF, does offer clear direction on aligning the diverse facets of function, structure and context (Magoulas et al., 2012).
The CIMOSA approach cannot be easily understood by practitioners due to its complicated content. It is also not a reference model for designing a system. However, CIMOSA is better known in the manufacturing industry. BMM and EBMM are good motivation models for top- down alignment, which helps to build a mature business architecture and can be federated for other aspects of corporate governance, e.g. risk management, SWOT analysis and quality assurance. BMM and EBMM lack a consideration of technology details.
The existing EAFs are constructed on disparate abstraction mechanisms. The perspectives, viewpoints, architectures and dimensions vary from one framework to another. Most of the frameworks are limited in terms of balancing among functionality, structure and behaviour, in the sense of what is it? What should it be? What might it be? Why do we need to do a particular thing? Why do we consider one option and not another? Frameworks should be developed considering rapidly evolving complex collaborative environments. Besides meeting the challenges of an uncertain and changing environment, enterprises are facing
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issues such as security breaches and scams in emergent human behaviour. Enterprises have to take strategic initiatives to address risks and issues. These threats have activated a spurt in the number of regulations and the importance of regulatory compliance. It is therefore important that organisations expand the scope of enterprise architectures to alleviate risk, thereby addressing regulatory and security requirements (CISCO, 2009). FEAF has already incorporated updates to IT security, privacy and risk management procedures (CIO, 2010).Most of the enterprise architecture models examined do not offer reasoning capability. Reasoning allows enterprises to understand the consequences of various scenarios and in the process supports decision-making. Most of the aspects of EAF lack one of clearness, communication, alignment or details (Ganesan, 2011). Several researchers have tried to solve these issues: in view of this, Ganesan (2011) proposed a framework which comprised seven basic components: motivation, governance, architecture, definition and modelling, tool administration, library management, stakeholder management and stakeholder training (Ganesan, 2011). This proposal from Ganesan (2011) suggests that all seven components are not available in their entirety in the current models.
There is an urgent need to structurally and functionally align the constitutional parts of enterprise architectures (Magoulas et al., 2012). According to Sessions (2007), the frameworks, namely the Zachman, TOGAF, FEAF and Gartner methodology, could be merged or blended to suit the requirements of an organisation. A comparative analysis of the twelve frameworks is shown in the table 7 below based on the criteria Scope, Metamodel, Methodology, Layers and abstraction, and other aspects.
TABLE 7: EAFS CRITIQUE
Analysis Aspect Explanation
Scope Most EAFs consider the whole enterprise structure (strategic, business
and technology). However, the Gartner process model is an iteration process focusing on continually closing the gap between requirements and current architecture. The ARIS model has a process-oriented focus on business operation, alignment, improvement and governance. The BMM and EBMM both have a business architecture focus with the capability to align with technical architecture.
Metamodel Not all EAFs provide semantic metamodels, and the metamodels fall
between the simple and complex. Zachman, EA3 cube, Gartner, ARIS and CIMOSA do not have metamodels. TOGAF, Archimate and FEAF have simple metamodels and frameworks such as DoDAF 2.0, EBMM and BMM have powerful and comprehensive semantic metamodels.
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TABLE 7: EAFS CRITIQUE (CONTINUE)Analysis Aspect Explanation
Methodology EAFs mostly do not have detailed implementation methodologies. In
most cases, they offer general guidelines or steps for implementation. TOGAF is considered the stronger from this point of view because of its offer, the ADM method for TOGAF initiation and implementation.
Layers and Abstraction
Non-Layers: BMM, EBMM, Gartner
Three and Four Layers: Archimate (3x3 matrix), FEAF (4 layers,
DoDAF 1.0 (3 views), ARIS (3 layers x 5 views), CIMOSA (3 layers x 4 views).
Five Layers: EA3 Cube, GERAM.
Six or more: Zachman (6x6 matrix), TOGAF (8 models +
Requirements model), DoDAF 2.0 (7 views).
Other Aspects A few frameworks such as Gartner, TOGAF and ARIS focus on
changing and maturity of requirements. However, reasoning and dynamic simulation capabilities are not considered. Risks have been discussed briefly in some of these frameworks, but no deep consideration has been provided.
The analysis of the various architecture frameworks reflects the fact that the strengths and weaknesses are evenly distributed. However, most models do not specify metamodels. It is therefore important that the specification of metamodels is made in order to guarantee the consistency of architecture descriptions (Leist and Zellner, 2006). It can therefore be concluded that none of the enterprise architecture frameworks provide a complete solution to the problems facing organisations in term of soft aspects, reasoning and dynamic modelling, while these are important elements to be considered while modelling the enterprises. In the next section, details about these problems and potential issues emerge from the gaps in the current methods.