Vorlesung Software Engineering
35
Software Engineering Research Group: Processes and Measurement Fachbereich Informatik TU Kaiserslautern Last update: 10/01/2012 Grundlagen des Software Engineering Fundamentals of Software Engineering Winter Term 2011/12 Prof. Dr. Dr. h. c. Dieter Rombach Chapter 5.4: Software System Engineering - Software Product Line Architecture
Transcript of Vorlesung Software Engineering
Software Engineering Research Group: Processes and Measurement
Fachbereich Informatik
TU Kaiserslautern
Last update: 10/01/2012
Grundlagen des Software Engineering Fundamentals of Software Engineering
Winter Term 2011/12
Prof. Dr. Dr. h. c. Dieter Rombach
Chapter 5.4: Software System Engineering -
Software Product Line Architecture
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 1
SW Product Line
Architecture Goals
The goals of this chapter are to be able to:
– Define product line engineering
– Understand the concept of commonalities and variabilities
– Understand SPL architectural concepts
– Understand variation modeling
– Characterize Kobra development approach
Literature
– C. Atkinson, J. Bayer, C. Bunse, O. Laitenberger, R. Laqua, E. Kamsties, D. Muthig, B.
Paech, J. Wüst, and J. Zettel. Component-based Product Line Engineering with
UML, Component Series, Addison-Wesley, 2001
– I. John and M. Eisenbarth, "A decade of scoping: a survey," in Proceedings of the 13th
International Software Product Line Conference, ser. SPLC '09. Pittsburgh, PA,
USA: Carnegie Mellon University, 2009, pp. 31-40.
– J. Lee and D. Muthig, "Feature-oriented variability management in product line
engineering," Commun. ACM, vol. 49, no. 12, pp. 55-59, Dec. 2006.
– D. Muthig and C. Atkinson, "Model-Driven product line architectures," in Software
Product Lines, ser. Lecture Notes in Computer Science, G. Chastek, Ed. Berlin,
Heidelberg: Springer Berlin / Heidelberg, Jul. 2002, vol. 2379, ch. 8, pp. 79-90.
– K. Pohl, G. Böckle, and F. J. Linden, Software Product Line Engineering: Foundations,
Principles and Techniques. Secaucus, NJ, USA: Springer-Verlag New York, Inc.,
2005.
– D. Weiss and C. Lai. Software Product Line Engineering - A Family-Based Software
Development Process, Addison-Wesley, 1999
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 2
SW Product Line
Architecture Motivation: Typical Challenges
For System-Developing Organizations
– Series of development projects (leverage on commonalities, reuse)
– „Increasing complexity of systems (avoid complexity explosion)
– Need for reducing cost, effort, and time-to-market (can be reduced via reuse)
– „Increasing request for quality solutions (certification hard w/o reuse)
– „Increasing demand for customized products (easy adaptation if anticipated)
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 3
SW Product Line
Architecture Variability in Time vs. Variability in Space [bachmann+05]
Variability
– the ability of a core asset to adapt to usages in the different product contexts that are
within the product line scope
Variability in Time (releases, dominant in IS)
– the existence of different versions of an artifact that are valid at different times
Variability in Space (variants, dominant in ES)
– the existence of an artifact in different shapes at the same time
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 4
SW Product Line
Architecture What is "Software Product Line Engineering" (SPLE)?
Software Product Line Engineering
– a paradigm to develop software applications using platforms and mass customization.
[Pohl+05]
Family/Domain Engineering (creating reusable artifacts)
– the process of software product line engineering in which the commonality and the
variability of the product line are defined and realized. [Pohl+05]
Application Engineering (creating customer applications from reusable artifacts)
– the process of software product line engineering in which the applications of the
product line are built by reusing domain artifacts and exploiting the product line
variability. [Pohl+05]
= +
SPLE
P2
Family Engineering
P2
Application Engineering
P2 P1 P3
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 5
SW Product Line
Architecture Life Cycle of a Software Product Line
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 6
SW Product Line
Architecture
Product Line Infrastructure
Domain
Product Line
Life Cycle
Domain
Family Engineering
Product
Line
Artifact Base
Fe
ed
ba
ck
Documentation
Identification
Classification Evolution
Coordination
Evaluation
Integration
Adaptation
Application Engineering
Product Product
Requirements
Requirements C
Requirements B
Product
Requirements A
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 7
SW Product Line
Architecture Scoping
Product Line Scoping is the process of identifying and bounding capabilities
(products, features) and areas (subdomains, existing assets) of the product line
where investment into reuse is economically useful and beneficial to product
development. [John+09]
[John+09]
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 8
SW Product Line
Architecture Scoping Example
Product Feature Matrix
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 10
SW Product Line
Architecture Goals of Software Product Line Engineering
Reduction in the time to market required for individual products
„Reduction in required development effort per application (product)
Reduction in overall development effort per product line
Increase in quality
etc. [Weiss+ 99]
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 11
SW Product Line
Architecture Product Line Economics – Development Effort
# Delivered System
1 2 3 4 5 6
Effort
Single
System
Investment
PL
Instance
Single System
Development
Product Line
Approach
Rule of thumb:
Savings begin
between 2nd
and 3rd product. Rule of thumb:
Investment
ranges
between
development
efforts for 1
and 2 systems.
[Weiss/Lai], [Fraunhofer PuLSE™],
etc.
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 12
SW Product Line
Architecture
# Delivered Products
1 2 3 4 5 6
Single-system
Development
(independent)
PL Engineering
(proactive)
PL Engineering
(reactive)
Single-system
Development
(clone-and-own)
Successful
Product Lines
Product Line Strategy – Product Line Economics (Revisited)
Effort
(~ TTM-1
~Cost)
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 13
SW Product Line
Architecture SW Architecture
Architecture is the first artifact that translates the problem into in the solution space
„Provides an overview on the system
„Enables early discussion and assessment of design alternatives
„Architecture is the output of the software design process
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 14
SW Product Line
Architecture PL System Architecture as a Mediator
Specification & decomposition of a whole family of systems
– covering the most important common design decisions
– supporting SW variations for system customization
Constraints & guidance of PL Implementation
– allowing parallelization of work in family and application engineering
– ensuring that the quality attributes can be achieved in all members of the PL
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 15
SW Product Line
Architecture What offers a product line architecture?
Enables making considerations about variability early on
„Product Line Architecture enables encapsulating the variability
[Mann+ 09]
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 16
SW Product Line
Architecture Architectural Drivers
Business goals
– Customer organization
– Developing organization
„Quality attributes
– System in use
– System under development
„Key functional requirements
– Unique properties
– Make system viable
„Constraints
– Organizational and technical
– Cost and time
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 17
SW Product Line
Architecture Architecture Usage Scenarios
and who are the stakeholders?
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 18
SW Product Line
Architecture Architecture stakeholders
General Architecture
stakeholders
Additional Architecture
stakeholders in a PL
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 19
SW Product Line
Architecture Fraunhofer Architecture Process
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 20
SW Product Line
Architecture Planning
Incremental definition of an architecture
– „ Align with project plan
System increments
Availability of necessary non-software components or artifacts
– First iteration typically addresses complete systems at a high level of abstraction
(conceptual view)
Scope of Iterations
– Document all required decisions (revisit if backtracking is necessary)
– Constrain decisions as little as possible (but as much as necessary)
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 21
SW Product Line
Architecture Realization
Refining quality requirements
– „Define main qualities
– „Identify categories of requirements
– „Identify and apply architectural scenarios
„
Identifying subsystems, components, and connectors
– „Check consistency, conformity, and completeness with respect to quality
requirements
– „Handling of constraints and alternatives
„Analyzing and mitigating risks
– „Prototyping
– „Reverse Engineering
Recording of design decisions and rationales
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 22
SW Product Line
Architecture Documentation: Views, Models, Diagrams
Architectural View
– A representation of a system from the perspective of a related set of concerns
Benefits
– Separation of Concerns
– Complexity reduction
– Communication with stakeholders
Idea: View-based Design and Analyses
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 23
SW Product Line
Architecture Variation Modeling in UML
Unified Modeling Language (UML) is commonly used to describe software
architectures — at least for object-oriented systems
„UML does not support the description of PLAs
– „UML tools do not support it, either
– „some UML tools support UML extensibility mechanisms
Stereotypes
Tagged Values (Properties)
Constraints
→ Find a workaround using UML extensibility options
– allows to use existing tools
– product line architectures comply to the UML standard
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 24
SW Product Line
Architecture Typical variant elements in UML
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 25
SW Product Line
Architecture Feature Modeling
Feature modeling
– is the activity of identifying externally visible characteristics of products in a product
line and organizing them into a feature model. [Lee+06]
Features
– can be services, operations, non-functional characteristics, and technologies of a
particular product line. [Lee+06]
Type
Car
[1..1]
Truck
Engine
Diesel Electricity
[1..1]
Petrol
Wheel Trunk Seat
Vehicle
Mandatory
Optional
Alternative [min..max]
Variability Dependencies
requires
excludes
Constraint Dependencies requires
excludes
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 26
SW Product Line
Architecture Decision Modeling
Decisions
– are variation points that typically constrain the resolution of other variation points.
[Muthig+02]
Each Decision defines a question that captures the essence of the related
variability
A Decision Model includes
– id
– decision name
– question
– variation point
– resolution & default
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 27
SW Product Line
Architecture KobrA – Generic Component Model Suite
KobrA
– a systematic method that integrates component-based development with product line
engineering [Atkinson+01]
– makes use of the extension mechanisms of the UML [Muthig+02]
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 28
SW Product Line
Architecture Basic Goals [Atkinson+01]
Simple
– a method with separate concerns
Systematic
– concepts and guidelines defined in the method should be precise and unambiguous
– tell developers what they should do, rather than what they may do
Scalable
– be able to accommodate large-scale and small-scale problems in the same manner
– the method should be applicable incrementally
Practical
– compatible with commonly used technologies
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 29
SW Product Line
Architecture Role of a Component Specification
To describe the externally visible properties of a component
Defines a component’s
– supplied services (supplied interface)
– acquired services (components)
Provides the basis for the contract between the component and its clients
„Is defined in the context of the parent component’s realization (or the context
realization if the root)
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 30
SW Product Line
Architecture Primary Specification Models
Structural model
– data manipulated by the component, its environment, and any externally visible
structure
– one or more class diagrams
– „zero or more object diagrams
„Functional model
– computations performed by the component
– one operation specification for each operation
Behavioral model
– states exhibited by the component and the events that change them
– „zero or more state chart diagrams
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 31
SW Product Line
Architecture Example: Structural Model
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 32
SW Product Line
Architecture Example: Functional Model
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 33
SW Product Line
Architecture Example: Behavioral Model
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 34
SW Product Line
Architecture Role of a Component Realization
To describe the way in which a component realizes the services specified in the
specification
Defines a component’s
– private subcomponents
– architecture and design
� Is defined in the context of the component’s specification
– the realization models expand upon the information in the specification model
SW Product Line
Engineering (SPLE)
Motivation
Defintion
Life cycle
Goals
SPL Architecture
Introduction
Usage
Process
Variation Modeling
Modeling in UML
Feature Model
Decision Model
Kobra
Introduction
Comp. Specification
Comp. Realization
© Prof. Dr. Dr. h. c. Dieter Rombach, Fundamentals of Software Engineering, Winter Term 2011/12 35
SW Product Line
Architecture Example: Phone Component
