Article - Principles Haki & Legner 2013

Question 1

What is EA according to Haki & Legner?

Answer 1

The fundamental organization of a system, embodied in its components, their relationships to each other and the environment, and the principles governing its design and evolution.

Question 2

What is included in EA artifacts?

Answer 2

1. Representation Models
   Conceptualized by means of different EA methods, models and frameworks
2. Principles
   Guiding principles for an architecture’s design and evolution.

Question 3

What are 5 general characteristics of principles?

Answer 3

1. Can be attributed to different architectural layers.
2. Should be based on business and IT strategies
3. Refer to the construction of an organization
4. Metrics can be identified for each principle to measure its fulfilment.
5. Each principle should be described in a principle statement, along with a rationale to explain why this principle is helpful in attaining a predetermined goal, as well as implications that describe how to implement the principle.

Question 4

What are the three most important characteristics for principles to be considered principles instead of non-principles?

Answer 4

1. Principles are used to govern architecture design and evolution;
2. Principles should be used to limit design space and guide design decisions;
3. Principles should harmonize IT projects to predefined (business) goals;

Question 5

What are three kinds of non-principles?

Answer 5

1. Confusion of principles and EAM goals
   (I.e. Develop competencies)
2. Confusion of principles and EAM practices
   (I.e. IS planning as integral part of business planning)
3. Confusion of principles with low-level governance means, representing standards and guidelines
   (I.e. Access rights must be granted at the lowest level necessary)

Question 6

Why is confusion with EAM goals a non-principle?

Answer 6

They do not limit design space or guide design decisions

Question 7

Why is confusion with EAM practices a non-principle?

Answer 7

They do not provide guidance or contribute to design decisions

Question 8

Why is confusion with governance a non-principle?

Answer 8

That is if they are low-level governance policies, which are merely standards - not principles.

Question 9

What are the most important principles (ranked according to experts) ?

Answer 9

1. Standardization
2. Compliance
3. Data consistency
4. Modularity
5. Reusability
6. Interoperability
7. Integration
8. Usability
9. Simplicity
10. Portability
11. Centralization

Question 10

What do experts want to change to the list?

Answer 10

• Remove centralization. Replace it with Technology Independence
• Add ‘Reduce technology variatons’ - can be added to standardization

Question 11

What is standardization?

Answer 11

Uniformity in data, documents, programming language, applications and processes. This reduces technical diversity and complexity

• Can be enforced through compliance

Question 12

What is compliance?

Answer 12

Conformity with corporate, industry specific and universal standards as well as laws and regulations.

-> supports standardization by setting procedures to enforce standards

Question 13

What is data consistency?

Answer 13

Level of shared definitions and consistency for stored data. Includes the degree to which datasets satisfy integrity constraints.

-> minimum requirement for integration

Question 14

What is modularity?

Answer 14

Degree to which an IT portfolio’s decomposition into loosely subsystems that communicate through standardized interfaces. Having minimum interdepenencies.

-> prerequisite of reusability

Question 15

What is reusability?

Answer 15

Having applications for common use. Develop them so that they an be used across the organization.

-> Requires modularity

Question 16

What is interoperability

Answer 16

Compatibility and connectivity among all hardware, software & communication components. Early design decision to ensure integration.

->Prerequisite for integration

Question 17

What is integration?

Answer 17

The integration of enterprise, process, data, application and infrastructure. Example: one application to access all functionalities.

-> Requires interoperability and data consistency

Question 18

What is usability?

Answer 18

Shared look-and-feel and support of ergonomic requirements. Note: strong emphasis on usability at the cost of functionality is not advised.

-> Requires simplicity in the interfaces

Question 19

What is simplicity?

Answer 19

Minimal dependencies between different modules in business and application and architecture

-> Supports usability (ease-of-use)

Question 20

What is portability?

Answer 20

Ability of a system to run in different computing environments. Leads to flexibility in hardware & vendor selection, lower cost and facilitates migration to new technologies.

Question 21

What is centralization?

Answer 21

Centralization of application components throughout the organization. Feasibility is questioned due to high cost.

Question 22

What does reusability improve?

Answer 22

Maintainability, quality, portability and software productivity.

Question 23

What two principles are required for integration?

Answer 23

1. Interoperability

2. Data consistency

Question 24

How can standardization be enforced?

Answer 24

Through compliance

Question 25

What is required for reusability?

Answer 25

Modularity

Question 26

What is required for usability?

Answer 26

Simplicity of interface architecture

Question 27

What are EA principles’ roles and application (4) ?

Answer 27

1. They should guide and limit design decisions
2. Enable reaching EA goals and keep consistency in the EA
3. High level granularity to impact EA decision on all enterprise levels
4. Limited number, understandable and supported by key members.