EA Flashcards
What are the five CORE components of EA
As-is = current state of organisation
to- be = future state (main focus of EA)
migration plan = from as-is to to-be
principles - guidelines for users of the architecture
decisions log = key part of ‘living’ architecture
what other theory is linked to EA
Strategic Alignment theory. Both address how designs of business and IT affect performance.
How is EA linked to the business model of a firm?
The Business Model of a firm defines the Value Proposition (what value is offered
to whom) and the Operating Model of a firm (how is the value created).
Business Models &Enterprise Architecture both define how, who, what, when, and where value is created (operating model) and for which markets (value proposition).
EA as a framework (Zachman). Draw and explain the picture.
Y-axis: Scope/contextual (planner view), enterprise model(conceptual) owner, system model(logic) designed
X- axis Data(what), Function(how), Network(where)
The Open Group Architecture Framework (TOGAF) process (phases). Explain the flow.
- prelim. framework and principles
- architecture vision
- business architecture
- IS architecture
- Technology architecture
- Opportunities and solutions
- Migration Planning
- Implementation Governance
- Architecture change management
Article 1992 Sowa and Zachman:
What does Zachman’s framework do?
It provides a systematic TAXONOMY or concepts for relating things in the real world to the representations in the computer. It provides a way of viewing a system from many perspectives and showing how they are all related.
Article 1992 Sowa and Zachman: rules of the framework.
Rule 1. Columns have no order. Order implies priority.
Rule 2. Each column has a simple, basic model. Columns are abstractions of real-world for convenience of design.
Rule 3. The basic model of each column must be unique.
Rule 4. Each row represents a distinct unique perspective.
Rule 5&6. Each cell is unique but they are related to other cells of the same column.
Article 1992 Sowa and Zachman: what tool/ method can you use to represent column B of the framework?
Petrinets can be used to represent processes.
Also any E-R diagram can be translated into a conceptual graph.
Article 2013 Kappelmann and Zachman: what is architecting/ architecture and why is it important?
Architecting is a kind of modeling. Every object has an architecture regardless if its explicitly written down or not.
If you can’t describe an object you can’t create it. If you need a team to help you create, change or manage the object and you can’t explain it, they cannot help.
Article 2013 Kappelmann and Zachman: when is architecture imperative ?
Only when the object you are trying to create is complex/ very complex.
Article 2013 Kappelmann and Zachman: zachman quadrant structure.
- resource ideas
- behavior ideas
- resource reality
- behavior reality
IT is more concerned about resource reality while management is more concerned about ideas.
Article Groot, Smits 2015: explain model with EA fit included.
Emerging business problem -> requires IT project proposal -> which results in IT projects portfolio -> which results in IS applications portfolio.
Emerging b. problem influecens internal drivers, which together with external drivers influence the architecture development process -> leading to enterprise architecture, which is the norm for both IT project proposals as well as for IT projects Portfolio.
Article Groot, Smits 2006: How does EA help emerging business problems?
without EA emerging business problems lead to complexity of the IS application portfolio and
design debt
• Such complexity of IT, high IT costs, or the emerging business problems, and poor IT flexibility are
internal drivers to start using EA
• External drivers for using EA can be legislation, standardization, or supervisory institutions
• EA development makes use of design principles (‘agreements between business and IT’)
• After establishing the IST and SOLL EA,
Article Groot, Smits 2015: Problem situation
IS portfolio is complex (esp after merger or acquisition)
Low IS flexibility & failing IS projects
Decentralized IS budget
Article Groot, Smits 2006: Challenge and solutions
How to redesign IS portfolio
How to reduce IS complexity
Solution: PICTURE APPROACH 1. Process 2. Products 3. Decisions
Picture Approach as EA method. Summary
PA is a method:
- helps analyze, redesign and combine system complexdes / portfolios
- fitting all in one as-is picture
- helps improve business - IT alignment
FOCUS of PA:
- process architecture
- information architecture
- organization architecture (who decides on what)
- IT architecture
The Picture Approach - EA process
List and describe the steps:
- establish support from PM and senior management
- make “photo-shoots” of core process, applications, documents, actors
- review the “photos” (models) by management team
- Detail the models by adding “fact sheets” that define: sustainability, functionality per app, process support, costs and benefits (per app), risks (per app and total)
- Freezing the photos of “as is”
- Choosing the target EA (“to-be” EA) using multi criteria decision analysis (analytical hierarchy planning).
Article Groot, Smits 2006: how many pictures needed?
- ONE picture to represent as-is architecture.
- min 1, but also 2-4 for to-be
For every picture, 5-6 factsheets needed
How does the Analytical Hierarchy Planning (AHP) help chose the optimal TO BE architercture?
AHP calculates ‘the best choice of two options’ given weights and performs a sensitivity analysis.
It uses a comparison matrix for Three TO BE architectures: it compares A with B and C, B with C for each subcriterion.
You need to ask MANAGERS and EXPERTS questions in order to evaluate/ set the weights.
“ How important do you think performance is for ICT architecture? what about Scalability, migratability, maintainability?”
What other PWC tools are there to reduce EA complexity? (explain number 1 with mapping)
1) Mapping applications (systems) to business processes.
Find out which apps (and how many) are used per business process.
Find out which apps are used by multiple b. processes
Which b. processes use similar apps (to reduce redundancy).
This finds out which apps could be taken out, which merged and how to prioritize apps. -> leads to changing the app portfolio
What other PWC tools are there to reduce EA complexity? (explain number 2 with portfolio)
2) Quality of the apps portfolio (PWC).
Model supports analysis of app portfolio:
It maps out apps based on technical quality (ask IT), functional quality (ask business) and costs (ask finance).
How?
XY graph with Y = functional quality (low to high); X = Technical Quality (low to high). Size of circles indicates yearly costs.
Y low, X low = replace
Y high, X low = technical improvements
Y low, X high = functional improvements
Y high, X high = healthy
What are the 3 EA approaches to reduce complexity?
- Zachman approach: develop the right models for each cell 5x6
- Picture approach (PWC): focus on the right modelling process
- The practical approach: two models for IS application portfolio management.
How to deal with complexity when you dont know the architecture of complex object? 4 options
- reverse engineer artifacts (costly)
- trial and error (risky)
- make assumptions
- just tear down and start over.
How do you asses size and complexity of software? + rule of thumb?
Make use of Function Point Analysis.
A function point measures amount of business functionality an IS provides to users.
Rule of thumb (Capers Jones): One function point requires on avg 100 lines of code.
How to estimate software renewal time (build from scratch)?
Capers Jones shows that larger systems costs more developer time per FP.
The more FP, the more decrease of productivity (exponential).
How to approximate the cost of a Function Point (FP)?
The more complex and reliable a system needs to be, the higher the FP cost.
2000 eur vs 12000 euro (practitioner vs military).
Types of complexity of IS app portfolio (groot, smits, kuipers)/ difference between the types?
Objective complexity: components (apps), interfaces, functions
Subjective complexity: perceived effort that is required, to understand and cope with the portfolio.
Internal Drivers for EA (why do some companies do EA?)
- audit purposes
- to manage the IT system portfolio
- reduce complexity
- prepare a merger or acquisition
- etc
