4.2 architecture introduction
Upcoming SlideShare
Loading in...5
×
 

Like this? Share it with your network

Share

4.2 architecture introduction

on

  • 937 views

architecture introduction ingo arnold

architecture introduction ingo arnold

Statistics

Views

Total Views
937
Views on SlideShare
937
Embed Views
0

Actions

Likes
1
Downloads
33
Comments
0

0 Embeds 0

No embeds

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment
  • Donkey cart Goods Small lanes and narrow streets Short distances had to be bridged
  • Whether this thing is considered a barrel for cucumber, carrots or wine or whether it’s considered a home, very much depends on viewpoint and perspective. If you don’t believe me go and talk to Diogenes
  • Urban places Flora and fauna

4.2 architecture introduction Presentation Transcript

  • 1. Software Life-Cycle Management Architecture Introduction © Ingo Arnold Department Computer Science University of Basel Process Models
  • 2. What do we deal with by the way?
    • We …
      • Plan & Define
      • Architect & establish
      • Maintain & operate
    • … our Company’s Information System …
    Department of Computer Sciences – University of Basel
  • 3. What do we deal with by the way?
    • What is a Company Information System?
      • Flight Booking System @ Lufthansa, Germany, mid 60ies
    Department of Computer Sciences – University of Basel
  • 4. What do we deal with by the way?
    • A Company Information System is comprised of ...
      • Processes
    Department of Computer Sciences – University of Basel
  • 5. What do we deal with by the way?
    • A Company Information System is comprised of ...
      • Function points and applications
    Department of Computer Sciences – University of Basel
  • 6. What do we deal with by the way?
    • A Company Information System is comprised of ...
      • Data, Data Structures and Data Containers (Folders, Binders et al)
    Department of Computer Sciences – University of Basel
  • 7. What do we deal with by the way?
    • A Company Information System is comprised of ...
      • Some sorts of technological infrastructure and underpinnings
    Department of Computer Sciences – University of Basel
  • 8. What do we deal with by the way?
    • What has changed is that ...
      • „ Things“ have taken off the ground
      • ... and become ...
        • Virtual
        • Clonable
        • Shippable
        • Configurable
        • Investigable
        • Deletable
      • .. far beyond what was possible in the „things“ world of the mid 60ies
    Department of Computer Sciences – University of Basel
  • 9. Architecture is not new
    • The Solution Architect in the 60ies had to arrange processes, data, applications, tools, spaces and other means, fundamental to the given business models …
    Department of Computer Sciences – University of Basel
  • 10. Architecture is not new
    • … similar to what the Solution Architects have to in 2008
    • ... just the means changed a bit in the meantime
    Department of Computer Sciences – University of Basel
  • 11. Architectural disorientation Why bother? Department of Computer Sciences – University of Basel
  • 12. Architectural disorientation
    • What is architecture?
    • What are you expected to do as an architect?
    • How is architecture manifested?
    A tube A brush Department of Computer Sciences – University of Basel
  • 13. Architectural disorientation
    • How do you distinguish good from bad architecture?
    • Where and when does architecture occur?
    • Why is architecture to be developed – why is it useful?
    • Whereby is architecture developed?
    • Who is responsible for architecture?
    • How do you approach architecture?
    • What do you need to know as an architect?
    Department of Computer Sciences – University of Basel
  • 14.
    • Architecture evolves in its context – Barcelona …
    Architectural disorientation Department of Computer Sciences – University of Basel
  • 15.
    • Architecture evolves in its context – Barcelona …
    Architectural disorientation Department of Computer Sciences – University of Basel
  • 16. All too often reality
    • We start with a „wish list“.
    • What follows is „a concept“.
    • A „first pilot“ is implemented.
    • The pilot goes life.
    • Changes are required.
    • To implement the changes we need to deviate from the original „concept“.
    Department of Computer Sciences – University of Basel
  • 17. All too often reality
    • Software architectecture was created:
    „ Big Ball of Mud“-Pattern In computer programming, Big Ball of Mud is a term for a system or computer program that has no real distinguishable architecture. It usually includes more than one of the other anti-patterns. Department of Computer Sciences – University of Basel
  • 18. All too often reality Department of Computer Sciences – University of Basel
  • 19. All too often reality Maintaining a shantytown is labor-intensive and requires a broad range of skills. One must be able to improvise repairs with the materials on-hand, and master tasks from roof repair to ad hoc sanitation. However, there is little of the sort of skilled specialization that one sees in a mature economy. Department of Computer Sciences – University of Basel
  • 20. All too often reality Department of Computer Sciences – University of Basel
  • 21. All too often reality All too many of our systems are, architecturally, little more than shantytowns. Investment in tools and infrastructure is too often inadequate. Tools are usually primitive, and infrastructure such as libraries and frameworks, is undercapitalized. Individual portions of the system grow unchecked, and the lack of infrastructure and architecture allows problems in one part of the system to erode and pollute adjacent portions. Department of Computer Sciences – University of Basel
  • 22. Question 4 you
    • What are symptoms of bad architecture?
    Department of Computer Sciences – University of Basel
  • 23. Symptoms of immature architectures
    • Results of analysis phase are not adequately considered.
    • Holistic view of IT-System is missing.
    • Complexity increases and becomes unmanageble.
    • Planning and risk-management becomes difficult.
    • Reuse of expertise as well as system building blocks is difficult.
    • Flexibility, maintainability, interoperability become a problem.
    • Architecture documentation is missing or not up-to-date.
    • Steep learning curve for new staff entering the project.
    Department of Computer Sciences – University of Basel
  • 24. Symptoms of immature architectures
    • Redundancy of code and functionality.
    • System‘s building blocks are heavily interdependent.
    • Very long development and change cycles.
    Department of Computer Sciences – University of Basel
  • 25. Symptoms of immature architectures System complexity Architecture relevance Department of Computer Sciences – University of Basel
  • 26. What is architecture?
    • Have you ever seen or touched Architecture?
    .. even here .. Department of Computer Sciences – University of Basel
  • 27. What is architecture?
    • We believe “No” ..
    Design-time Perspective System Perspective (Physics) Department of Computer Sciences – University of Basel
  • 28. What is architecture?
    • Architecture is an inherent aspect of any system
    • But you can’t see nor can you touch it on the system level
    • Architecture is tangible only on the level of models and plans
    • Architecture is mainly about quality .. not functionality
    • Architecture has a mid- to long-term ROI .. you cannot avoid it
    Architecture Perspective (Models & Plans) Department of Computer Sciences – University of Basel
  • 29. What is architecture?
    • Architecture of a computer or IT-system is not immediately tangible. Nevertheless does every IT-system have an architecture
    • There are many architecture definitions out there, which are typically comprised of the following aspects:
      • Structure
      • Behaviour and collaboration of architectural building blocks
      • Discipline and methodology
    • Architecture covers everything .. from a system‘s problem domain analysis phase up to this system‘s retirement
    • Architecture makes complexity manageable by focussing onto only the substantial aspects of an IT-system
    System People Department of Computer Sciences – University of Basel
  • 30. What is architecture?
    • An Architecture defines behavior
    Department of Computer Sciences – University of Basel
  • 31. What is architecture?
    • An Architecture Balances Stakeholder Needs
      • The needs of the end user are associated with intuitive and correct behavior, performance, reliability, usability, availability, and security.
      • The needs of the system administrator are associated with intuitive behavior, administration, and tools to aid monitoring.
      • The needs of the marketer are associated with competitive features, time to market, positioning with other products, and cost.
      • The needs of the customer are associated with cost, stability, and schedule.
      • The needs of the developer are associated with clear requirements and a simple, consistent design approach.
      • The needs of the project manager are associated with predictability in the tracking of the project, schedule, productive use of resources, and budget.
      • The needs of the maintainer are associated with a comprehensible, consistent, and documented design approach, as well as the ease with which modifications can be made
    Department of Computer Sciences – University of Basel
  • 32. What is architecture?
    • An Architecture May Conform to an Architectural Style
      • Every well-structured software-intensive system is full of patterns. (Booch 2009)
      • An architectural style defines a family of systems in terms of a pattern of structural organization. More specifically, an architectural style defines a vocabulary of components and connector types, and a set of constraints on how they can be combined. (Shaw 1996)
    • An Architecture is influenced by its environment
    • Architecture is not concerned with a system‘s fine grained structures and elements (i.e. classes, objects, algorithms) but instead with such system‘s coarse-grained components and building blocks
    Department of Computer Sciences – University of Basel
  • 33. What is architecture?
    • Architecture is concerned with all decisions which are difficult to be changed later on
    • Architecture is more than just the result of an architect‘s design-activities – architecture is a science in its own right
    • Architecture and Design are two sides of the same coin:
      • All respective activities, decision making, ways of thinking are no different at all
      • Architectural Decisions just have a wide ranging impact (across the system)
      • Design decisions have a rather local and isolated scope (e.g. sub-system)
    • Architecture aims at sustaining investments
    United Nations – Sustainability “ Sustainability means meeting the needs of the presence without compromising the needs of the future” Department of Computer Sciences – University of Basel
  • 34. What is architecture?
    • Architecture is concerned with Macro-Structures of a system. Well, here the question remains: „what are such macro-structures?“
      • For example, lock-strategies for persistence-stores …
      • … or addressing schema length (e.g. 32-bit versus 64-bit) seem pretty low-level technical at a first glance
      • However, if they have a significant impact on the system’s ability to evolve and scale over time they are architectural
    Department of Computer Sciences – University of Basel
  • 35. What is architecture?
    • Architecture contributes to the non-functional capabilities of our systems, where investments are vital & crucial but also have a diminishing ROI
    Department of Computer Sciences – University of Basel
  • 36. What is architecture? Well – and there are a few more ;-)
    • First we make our Systems – then our Systems make us
    • We make Software like we make cathedrals – first we make them and then we pray
    Department of Computer Sciences – University of Basel
  • 37. What is architecture? The spirit of architecture
    • What’s so cool about the SAPs of this world?
    Company A Company B Company C 20 % customizing 80 % COTS Department of Computer Sciences – University of Basel
  • 38. What is architecture? The spirit of architecture
    • Frameworks are applied architecture
      • Hollywood principle (  „don‘t call us – we call you“ )
      • Architecture constraints – it controls potential developer-freedom based on a system‘s fundamental structures (e.g. backbone process logic).
    Department of Computer Sciences – University of Basel
  • 39. What is architecture? The spirit of architecture
    • Frameworks are applied architecture
      • Architecture guides.
      • Architecture reduces complexity by offering dedicated extension points.
      • Architecture frees up developers from architectural decision making (i.e. Backbone process logic).
    Department of Computer Sciences – University of Basel
  • 40. What is architecture? The spirit of architecture
    • Frameworks are applied architecture
      • The SAP system is an HR generic process expert.
      • Novartis is an expert in their specific HR process requirements.
      • The overall architecture balances these forces and allows for both, controlled evolution and governance, as well as flexibility.
    Example Department of Computer Sciences – University of Basel
  • 41. Architecture – Definition
    • “ The software architecture of a program or computing system is the structure or structures of the system, which comprise software components, the externally visible properties of those components, and the relationships among them ” [Bass et al]
    Department of Computer Sciences – University of Basel
  • 42. Architecture – Definition
    • Architecture is concerned with ...
      • the structure and structure(s) of a system ..
      • its individual building blocks or components ..
      • their externally visible properties ..
      • as well as their relationships amongst these.
    Department of Computer Sciences – University of Basel
  • 43. Architecture – Definition
    • Architecture is concerned with the main pillars of a computer-system – not with this system‘s details ..
    Department of Computer Sciences – University of Basel
  • 44. Architecture – Definition
    • .. but what the main pillars are, depends on viewpoint and perspective!
    Solution context A Solution context B Department of Computer Sciences – University of Basel
  • 45. Architecture – Definition
    • .. but what the main pillars are, depends on viewpoint and perspective!
    Department of Computer Sciences – University of Basel
  • 46. Architecture – Definition Areas of Engagement Department of Computer Sciences – University of Basel Strategic alignment & planning perspective with a focus on smoothly underpinning the continuous evolution of the overal IT Service landscape Quality of Application and Infrastructure Service landscapes with a clear focus on providing holistic views and view models for planning purposes
    • Quality of individual Application and Infrastructure Services with a focus on quality attributes:
    • Stability
    • Performance
    • Extensibility
    • Security
    • Maintainability
    Application & Infrastructure Architecture Domain & Enterprise Architecture IT Planning & Strategy
  • 47. Architecture – Definition Areas of Engagement Department of Computer Sciences – University of Basel Architecture related Activities Govern vs Perform Application vs Infrastructure Services CCMOR Services Enterprise vs Domain vs Service Trends & Innovation Consulting Communication Planning & Roadmaps Requirements Dependencies Concept & Design PoCs & Candidates Review & Verification Documentation Trends & Innovation Training & Education Assessment Establish rules & policies Execute rules & policies Application Processes, Application, Data, Interfaces, … Infrastructure Middleware, Server, Storage, Frameworks, Network, Data Centers, … Create Change Migrate Operate Retire Enterprise (All) Domain (Many) Service (Single) X X X X
  • 48. Architecture – Definition
    • Architecture contributes to the non-functional capabilities (  qualities) of a system as well as to its longevity
      • Extensibility ( Quickly add PDF as a new UI channel )
      • Adaptability and changebility ( Add the role Supervisor to our system )
      • Reusability ( Reuse the Shopping Cart we developed for our portal )
      • Managability ( Grant the aquired company’s employees access to S )
      • Security ( Encrypt all data that goes into this database )
      • Availability ( Make sure the service is always up and running )
      • Scalability ( A marketing campaign is going to increase load on Site S )
      • Performance ( S is only used if search-result response time is below x )
    Department of Computer Sciences – University of Basel
  • 49. Architecture – Definition
    • Architecture shows the holistic whole only if all appropriate views are combined.
    Function / Process View Stakeholder View Component View Operational View Deployment View Host and operate Package and deploy Implement Function Serve Function 1 Function 2 Function 3 Department of Computer Sciences – University of Basel
  • 50. Architecture – Definition
    • Architecture shows the holistic whole only if all appropriate views are combined .. but this should be done in order ..
    Department of Computer Sciences – University of Basel
  • 51. Architecture – Definition
    • Architecture shows the holistic whole only if all appropriate views are combined .. as shown here (Aarau Photo)
    Department of Computer Sciences – University of Basel
  • 52. Architecture – Definition
    • Architecture shows the holistic whole only if all appropriate views are combined .. as shown here (Aarau Model)
    Department of Computer Sciences – University of Basel
  • 53. Architecture – Definition
    • Architecture shows the holistic whole only if all appropriate views are combined .. as shown here (Public Transport)
    Department of Computer Sciences – University of Basel
  • 54. Architecture – Definition
    • Architecture shows the holistic whole only if all appropriate views are combined .. as shown here (Denisity of Populat.)
    Department of Computer Sciences – University of Basel
  • 55. Architecture – Definition
    • Architecture shows the holistic whole only if all appropriate views are combined .. as shown here (Buffer Zones)
    Department of Computer Sciences – University of Basel
  • 56. Architecture – Definition
    • Architecture shows the holistic whole only if all appropriate views are combined .. Zoom-Level is similarily important ..
    Department of Computer Sciences – University of Basel
  • 57. Architecture – Definition
    • Architecture shows the holistic whole only if all appropriate views are combined .. as filters ..
    Department of Computer Sciences – University of Basel
  • 58. Architecture – Definition
    • Architecture needs to be managed
      • One System
      • Many Systems
    Department of Computer Sciences – University of Basel
  • 59. Architecture – Definition
    • Architecture needs to be managed over time
      • Yesterday ..
      • Tomorrow
    Department of Computer Sciences – University of Basel
  • 60. Architecture – Definition
    • IT-Systems become increasingly more complex, which naturally leads to more specialised architectural domains and disciplines:
      • Enterprise-Architecture.
      • Software-Architecture.
      • Data-Architecture.
      • Integration-Architecture.
      • Network-Architecture.
      • Security-Architecture.
      • System-Management-Architecture.
      • Etc.
    • One singular IT-System requires its overall architecture to take into consideration most – if not all – of the above listed areas and disciplines.
    Department of Computer Sciences – University of Basel
  • 61. Architect
    • The Architect
      • is a Technical Leader
      • role may be fulfilled by a team
      • understands the system development process
      • has knowledge of his business or technology domain
      • has technology knowledge
      • has design skills
      • has programming skills
      • is a good communicator
      • makes decisions by balancing tradoffs
      • is aware of organisations’ politics
      • is a negotiator
    Department of Computer Sciences – University of Basel
  • 62. Architecting
    • Architecting
      • is an art
      • spans multiple disciplines
      • is an ongoing activity
      • is driven by many stakeholders
      • often involves making tradeoffs
      • acknowledges experience
      • is both top-down and bottom-up
    Department of Computer Sciences – University of Basel
  • 63. Architecting The benefits of Architecting
    • The benefits of Architecting
      • it addresses system qualities
      • it drives consensus
      • it supports the planning process
      • it drives architectural integrity
      • it helps manage complexity
      • it provides a basis for reuse
      • it reduces maintenance costs
      • it supports impact analysis
    Department of Computer Sciences – University of Basel
  • 64. Questions? Department of Computer Sciences – University of Basel