Week 3: EA as a method Flashcards
The Open Group Architecture Framework (TOGAF)
A method to develop and manage the enterprise architecture. It is composed of multiple techniques and best practices. TOGAF advises to use Archimate as the EA toolset.
Drivers for EA as addressed by the picture approach
- Problem situation:
+ IS portfolio is complex (mostly after merger or acquisition).
+ Decentralized IS budgets
+ Low flexibility of IS & failing IS and business projects. - Challenge:
+ How to redesign the IS portfolio
+ How to reduce IS complexity
+ Diversity of IS models
+ Stakeholder are enemies - Solution: Picture approach
+ Process: pressure-cooker model, shared meaning.
+ Products: picture, fact sheets
+ Decision: multi-criteria analysis, analytical hierarchy planning.
Picture approach
- Approves, redesigns and combines system complexes (application portfolios).
- Improves business IT alignment in organizations.
Focus of picture approach
The application portfolio (IS architecture) plus relations to:
- Process architecture
- Information architecture
- Organization architecture
- IT architecture
Picture
A picture is an image of the organizational processes. This image maps out the functions of various IS applications in the processes. The fact sheets specify data and technologies.
Steps of the picture approach
- Several photo-shoots -> core process applications, documents and actors.
- Review of the photos (models) by the management team.
- Detailing the photos (models), adding fact sheets that define the following:
- Sustainability of the current and possible architectures.
- Functionality per application.
- Process support -> degree to which systems support the processes.
- Costs and benefits per application.
- Risks per application and total risk. - Freezing the photos (models) of the as-is and (some) to-be situations.
- Choosing the target EA (the to-be EA) using multi criteria decision analysis (analytical hierarchy planning).
Questions to support making a picture (PwC)
Questions regarding:
- Data and information
- Organization and processes
- Application and processes
Two main questions:
1. How many to-be pictures/architectures do you need?
2. How to choose the right to-be architecture?
+ can be done by using the Analytical Hierarchy Planning (AHP)
Tools to reduce EA complexity
- Mapping applications to business processes.
2. Quality of the applications portfolio
Mapping applications to business processes
Supports analysis of application portfolio:
- Which applications and how many are used per business process?
- Which applications are used by multiple business processes.
- Which business processes use (similar) applications (possible redundancy of applications)
To support management decisions on:
- Which applications may be phased out
- Which applications may be merged
- Prioritization of applications.
This leads to a project portfolio, and in the end changing the application portfolio.
Quality of the applications portfolio
Supports the analysis of the application portfolio:
- Technical quality
- Functional quality
- Costs
Then, decisions can be made on (e.g.):
- Which applications to improve technically.
- Which applications to improve functionally.
- Efficiency/Cost measures.
- Which applications to replace.
This leads to a project portfolio, and in the end changing the application portfolio.
3 EA approaches
- Zachman approach: focus on the right models.
- Picture approach: focus on the right modelling process.
- Practical approach: use the two models for IS application portfolio management.
Function point
A unit of measurement to express the amount of business functionality of an IS to a user. Used to compute a functional size measurement (FSM) of software.
Rules of thumb function points
- One function point requires on average 100 lines of code.
- 10.000 function points require 1 million lines of programming.
Objective complexity
What you can see:
- # Components (applications)
- # Interfaces
- # Functions (function point analysis)
How to reduce objective complexity?
- Reduce the # components per system and portfolio.
- Reduce the # interfaces (relationships) between systems
- Reduce the # functions