Implementation Workflow

Transcription

1 Implementation Workflow Michael Fourman

2 Introduction Implement the design in terms of components source code, scripts, binaries, executables, etc. Flesh out the architecture Plan system integrations in each iteration incremental: small, manageable steps Distribute system: map components to nodes focus on active classes Implement design classes and subsystems Unit test components Integrate components (compile and link into one or more executables) for integration and system tests Focus of construction phase architecture baseline in elaboration phase; defects in transition phase

3 Implementation Focus Core Workflows Phases Inception Elaboration Construction Transition Requirements Analysis Design Implementation Test Preliminary 1 2 n n+1 n+2 m m+1 Iterations

4 Artifacts Implementation Model Component Implementation Subsystem Interface Architecture Description Implementation view of architecture Integration Build Plan Sequence of builds in an iteration Functionality in each build Note: keep design model current via round-trip engineering Design model provides a visualization of implementation model

5 Implementation Workflow Activities and Workers Architect Architectural Implementation System Integrator Integrate System Component Engineer Implement a Subsystem Implement a Class Perform a Unit Test

6 Implementation Model Describes how elements of design model are implemented in terms of components such as source code, executables, etc. Describe how components are organized using the structuring and modularization mechanisms of the implementation environment and programming languages Hierarchy of Implementation (sub)systems containing Components and Interfaces Describe how components depend on each other

7 Component Physical packaging of model elements Standard stereotypes <<executable>> -- a program that may run on a node <<file>> -- file containing source code or data <<library>> -- static or dynamic library <<table>> -- a database table <<document>> -- a document technology specific (<<ActiveX>>, <<Applet>>, <<DLL>>, <<CORBA Component>>, etc.)

8 Component Characteristics Components trace to the model elements they implement (hence all the way back to use cases) A component usually implements several elements Components provide the same interfaces as the model elements they implement Compilation dependencies denote which components are required to compile a specific component Implement component stubs to ease compilation, integration and test

9 Trace between implementation and design Design Model Implementation Model AccountTransfers <<trace>> <<file>> AccountTransfers.java Transfers Transfers

10 Implementation subsystem Organize implementation model artifacts into more manageable pieces Manifested by a packaging mechanism in implementation environment package in Java project in VB, VC++ directory in C++ CORBA server in CORBA Component View package in Rational Rose Trace one-to-one with design subsystems same dependencies to other subsystems, interfaces provides same interfaces maps one-to-one with which components or other implementation subsystems within the subsystem provide the interfaces of the subsystem may need to iterate design to change the structure

11 Interface As in design, interfaces define the operations implemented by components and implementation subsystems A component that realizes (and thus provides) an interface must implement all the operations defined by the interface A subsystem that realizes (and thus provides) an interface must also contain components that provide the interface or other subsystems (recursively) that provide the interface

12 Architecture description Architectural view of implementation model Decomposition of implementation model into subsystems, their interfaces, and dependencies between them redundant with architectural view of design model due to one-to-one mapping Key components trace to architecturally significant design classes executable components components that are general, central, or implement generic design mechanisms that many other components depend on

13 4+1 View of Architecture and the workflows that define the views Analysis Implementation Logical View Functionality Use Case View Implementation View Software management Process View Performance, scalability, throughput Design Understandability Usability Requirements Deployment View System topology, delivery, installation, communication Design

14 Integration Build Plan Incremental build in small, manageable steps limits scope of integration and test problems build is an executable version of system should put the build under version control so can roll back on test failure Build plan for each increment list of functionality: use cases and/or scenarios list of implementation subsystems and components Test each build, including regression tests Typically multiple builds per iteration Benefits early executable system reduces risk start integration tests early easier to locate defects integration tests are more thorough than system tests

15 Workers Architect Responsible for the integrity of the implementation model (correct, consistent and readable as a whole) Component engineer Defines and maintains source code of several file components Maintains integrity of one or more implementation subsystems Typically the designer of the corresponding subsystems System integrator Plan build sequence Integrating each build from implemented parts

16 Details and Guidelines Architectural implementation Identifying architecturally significant components Identifying executable components and deploying them to nodes Integrate system Planning a subsequent build Integrating a build Implement a subsystem Maintaining the subsystem contents Implement a class Outlining file components that will contain source code Generating code from a design class and its relationships Implementing operations in terms of methods Making the component provide the right interfaces Perform unit tests Perform specification testing (black box; external) Perform structure testing (white box; internal)

17 Summary Implementation Model Implementation (sub)systems and their dependencies, interfaces and contents Components File and executable components Dependencies Components unit tested Architecture view of implementation model Integration Build Plan Each build from implementation is integration tested and system tested in Test Workflow