Lecture 3: EA as a method for change Flashcards
What is the picture approach?
A method for analysing, redesigning and combining system complexes and for improving business IT alignment in organizations.
from complex portfolio of IS -> migrate to a new single system complex
What are internal drivers to start using EA?
- High complexity of IT environment (EA) (high IT costs)
- Emerging business problems (and poor flexibility)
What are external drivers to start using EA?
Legislation, standarization, or supervisory institutions
What are the steps for the picture approach?
- Serveral ‘Photo-shoots’ -> core process, applications, documents, actors
- Review of the photos (models) by management team
- Detailing the photos (models), adding fact sheets that define:
- 1: sustainability (of architecture)
- 2: Functionality (per application)
- 3: Process support (degree of systems supporting processes)
- 4: Cost and benefits (per application)
- 5: Risks (per application and total risk)
- Freezing the models of the as-is and (some) to-be situations
- Choosing the target EA (using multi criteria decision analysis)
What other two (PWC) tools can be used to reduce EA complexity?
- Mapping applications to business processes (Excel sheet)
2. Quality of the applications portfolio (functional quality vs technical quality)
What is function point?
A unit of measurement to express the amount of business functionality an information system (as a product) provides to a user. (used for assesing size and complexity of software)
Rule of thumb: one function point requires on average around 100 lines of code.
How can complexity of IS application portfolio be reduced?
1Q. Objective complexity : # components (applications), # interfaces, # functions (FP)
1A: Reduce # components per systems & portfolio, reduce # interfaces between systems, reduce # functions
2Q: Subjective complexity: the effort (perceived by actors) to understand and cope with the portfolio
2A: Reduce the effort to understand the portfolio (visual main parts), support decision making using AHP (group support system + distinguish criteria + weights and objectives.
What are EA design principles?
Are use to limit design space and guide design decisions regarding architecture design decision points to harmonize IT projects.
What EA Meta principles are there for guiding EA design and evolution?
Modularity, integration, interoperability, standardization, data consistenccy, compliance, reusability, portability, usability, simplicity, centralization
Which fact sheets are there in the picture approach?
The picture approach specifies data and technologies.
- (sustainability of the) IT infrastructure
- systems functionality
- process support
- costs
- risks of the system complexes
On what four points does the picture approach focus?
- Process architecture
- Information architecture
- Organization architecture
- IT infrastructure
At what four leves is information logistics analyzed? (Robert Winter, St gallen)
- Job A -> job B (in department A)
- Department A -> department B
- Business unit A -> business unit B
- Company A -> company B
What does the PWC mapping applications to business processes analyse?
- which applications are used per business process
- which applications are used by multiple business processes
- which business processes use similar applications (redundancy)
it support managerial decisions on:
- which application may be phased out
- which applications may be merged
- prioritization of applications
What does PWC’s quality of the application’s portfolio analyse?
- technical quality
- functional quality
- costs
- which applications to improve technically
- which applications to improve functionally
- efficiency/cost measures
- which applications to replace
What three approaches to EA change are there?
- Zachman -> focus on the right models
- picture approach -> focus on the right modeling process
- practical approach -> use the two models for IS application portfolio management
(choice depends on the firm maturity, design principles and EA complexity)
What are all internal drivers for EA?
- Audit ( of systems, processes, data. Evaluating the current IST situation)
- specify management information: which data are needed to do business
- manage IT system portfolio: which are our core applications
- manage outsourcing relationships: which IT services must be internal
- guide systems development: specify IST and SOLL situations)
- perparing a merger or acquisition
- reducing complexity: of the IT portfolio, applications and processes
Results of a lack of architecture are?
- performance problems
- > 50% of projects exceed budget or time schedule
- 28% of projects fail
- lots of data, yet little information
- small functional changes lead to big effects
What are the benefits of a good architecture?
- clear boundaries of functional components
- predictable estimates for cost and schedule IT projects
- high availability
- reduced costs of ownership of IT operations
How to spot design debts?
- no visible architectural champion
- lack of balance between business and IT department (mainly NPV) driven
- no decomissioning strategy
- duplicate systems
What are architectural principles?
- principles have a raionale: why are we doing this?
- principles have an implication: we can no longer do this.
They are sign posts on the journey
- they underpin our investigations when we look at architectural options
- they are used to justify the decision we make about the components in an architecture
- they ensure that the architecture we define is consistent and keeps us on our path
What two types of principles are there?
- commandments: these just make sense
2. spectrum principles: two doable options that have opposing arguments
What are design principles?
EA principles should be used to
- limit design space
- guide design decisions
they should concern architecture design decision points so as to harmonize IT porjects towards predefined goals
EA principles -> quality of the EA -> EA benefits