se318 chapter29 part 1 exercises
TRANSCRIPT
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 1/31
Question 28.8
• Give two advantages and disadvantages of
the approach to process assessment and
improvement that is embodied in the process
improvement frameworks such as the CMMI.
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 2/31
Answer 28.8
Advantages of process improvement
frameworks
• 1-) Provides a means of measuring the state of
a process and a structured approach to
introducing process improvements.
• 2-) Useful as a way of building on the
experience of others in process improvement.
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 3/31
Answer 28.8
Disadvantages of process improvementframeworks
• 1-) Like any measurement system, there is a
tendency to introduce improvements toimprove the measured rating rather thanconcentrate on improvements that meet realbusiness goals.
• 2-) Expensive and bureaucratic to operate. Notsuitable for agile approaches.
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 4/31
CHAPTER 29
Configuration Management(CM)
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 5/31
Pre Info
• Requirements always change during
development and use.
• It is a must to incorporate these requirments
into new versions.
• That’s why you need to manage evolving
systems because it is easy to lose track of
what changes have been done.
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 6/31
Pre Info
Versions incorporate proposals for;
• Change
•
Corrections of faults• Adaptations for different hardware and
operating systems.
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 7/31
What is CM?
• Configuration management is the
development and use of standards and
procedures for managing an evolving software
system.
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 8/31
What does CM do?
• Define how to record and process proposed
system changes
• Identify different versions of the system.
• Store versions of the system components
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 9/31
What if you don’t have CM!!
• modify wrong version of a system
• Deliver wrong version
•
Lose track
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 10/31
System Families
Server
version
Linux
version
PC versionInitial
system
Desktop
versionWindows XP
version
HP
version
Sun
version
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 11/31
Configuration Management Planning
• Describes the standards and procedures that
should be used for configuration
management.
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 12/31
Configuration Management Planning
• It is organised into a number of sections asfollows;
• 1-Define what is to be managed.
•
2-Set out who is responsible• 3-Defines policies for change control and version
management.
• 4- Describes the tools which should be used to
assist the CM process(CVS version management)• 5-Defines the CM database used to record
configuration information.
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 13/31
Configuration Item Identification
In large systems there may be thousands of
• source code modules
•
Test scripts• Design documents
They are created by different people with
identical names
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 14/31
Configuration Item Identification
• To keep track of all this information so that the
right file can be found when it is needed.
• That’s why you need a consistent
identification scheme.
• Exp. PCL-TOOLS/EDIT/FORMS/DISPLAY/AST-INTERFACE/CODE
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 15/31
Configuration hierarchy
PCL-TOOLS
EDIT
STRUCTURES
BIND
FORM
COMPILE MAKE-GEN
HELP
DISP LAY QUERY
AST-INTERFACEFORM-SPECS FORM-IO
CODEOBJECTS TESTS
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 16/31
Configuration Database
• Is used to record all relevant information
about system configurations and configuration
items.
• It also keeps data to answer such questions as
follows;
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 17/31
Configuration Database
• 1-Which customers have taken delivery of particularversion of the system?
• 2-What hardware and operating system configurationis requried to run a given system version?
• 3-How many versions of a system have been createdand what were their creation dates?
• 4-What versions of a system might be affected if aparticular component is changed?
•
5-How many change requests are outstanding on aparticular version?
• 6-How many reported faults exist in a particularversion?
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 18/31
Change Management
• Software systems are subject to continualchange requests:
– From users;
– From developers; – From market forces.
• Change management is concerned with
keeping track of these changes and ensuringthat they are implemented in the most cost-effective way.
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 19/31
Request change by completing a change request fo
Analyze change request
if change is validthen
Assess how change might be implemented
Assess change cost
Submit request to change control boardif change is acceptedthen
repeat make changes to software
submit changed software for quality approval
until software quality is adequate
create new system version
else reject change request
else reject change request
The change management process
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 20/31
Change request form
Change Request Form
Project: Proteus/PCL-Tools Number: 23/02Change requester: I. Sommerville Date: 1/12/02Requested change: When a component is selected from the structure, displaythe name of the file where it is stored.
Change analyser:G. Dean Analysis date:10/12/02Components af fected: Display-Icon.Select, Display-Icon.Display
Associated components: FileTable
Change assessment: Relatively simple to implement as a file name table isavailable. Requires the design and implementation ofa display field. No changesto associated components are required.
Change priority:Low
Change implementation:Estimated effort: 0.5 days
Date to CCB: 15/12/02 CCB decision date:1/2/03CCB decision:Accept change. Change to be implemented in Release 2.1.Change implementor: Date of change:Date submitted to QA: QAdecision:Date submitted to CM:Comments
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 21/31
Version and Release Management
The goals are
• Identify versions
•
Keep track of the versions
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 22/31
What is version of a system?
Version is an instance of a system which differs the
current instance from others.
Versions of a system occurs from different reasons.
• different functionality
• Improved performance
• Repaired faults
• Designed from different hardware or software
configurations
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 23/31
Version Identification
In large system, there are hundreds of software
components, can exists in different versions.
That is why we need identification...
3 types;
• Version numbering
•
Attribute-based identification• Change-oriented identification
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 24/31
Version numbering
• A version number is added to the component
or system name.
• Example;
• 1.0
• 1.1
•
2.1.1
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 25/31
Version derivation Structure
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 26/31
Attribute-based identification
This type includes identifying attributes;
• Customer
• Development language
• Hardware platform
• Creation date
• Example: AC3D(language=Java,platform =XP,date=Jan2003)
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 27/31
Change-oriented identification
• To retrieve a version, you need to discover the
relationships between versions and changes.
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 28/31
Release Management
System release managers are responsible of;
• Deciding when the system can be released to
customers
• Process of creating the release
• Distribution media (CD..)
•
Documenting the release
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 29/31
Release Management
A system release is not just the executable code
of the system. The release includes more;
• Configuration files
• Data files
• An installation program
•
Electronic and paper documentation
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 30/31
Release Decision Making
If releases are too frequent
• Customers may not upgrade to new release
If releases are infrequent
• Market share can decrease
These are not for custom softwares
• For those, infrequent release may meanincreasing divergence from its functionalities
8/10/2019 SE318 Chapter29 Part 1 Exercises
http://slidepdf.com/reader/full/se318-chapter29-part-1-exercises 31/31
Factors influencing system release
strategy
Facto r Description
Technical quality of the system
If serious system faults are reported which affect the way in whichmany customers use the system, it may be necessary to issue a fault
repair release. Howeve r, minor system faults may be repaired by issuing patches (often distributed over the Internet) that can be applied to the
current release of the system.
Platform change s You may have to create a new release of a software application when anew version of the operating system platform is released.
LehmanÕs fifth law(see Chapter 21)
This sugge sts that the increment of functionality that is included in eachrelease is approximately constant. Therefore, if there has been a system
release with significant new functionality , then it may have to befollowed by a repair release.
Competition A new system release may be necessary because a co mpeting p roduct is
available.Marketingrequirements
The marketing d epartment of an organisation may have made acommitment for releases to be available at a particular date.
Customer change proposals
For customised systems, customers may have made and paid for aspecific set of system change proposals and they expect a system release
as soon as these have been implemented.