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Software Deployment,Maintenance &
Evolution
REKAYASA PERANGKAT LUNAK
Semester Ganjil 2015/2016
ADAM HENDRA BRATA
Deployment
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Definition
The delivery, assembly and management at a
site of the resources necessary to use a version
of a software system make a software
system available to its users
A software system is a coherent collection of
artifacts, such as executable files, source code,
data files, and documentation, that are needed at
a site to offer some functionalities to the end
users
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Urgency
Software systems are no longer merely stand-
alone applications
Increasingly, software systems are the integration
of a collection of components, both executable
and data, possibly dispersed over numerous
heterogeneous networked nodes
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ProcessesS
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Processes
Release Interface between developers and actors/users
The software is assembled into packages
containing sufficient metadata to describe the
resources on which it depends
It includes packaging and advertising
Installation The software is transferred to the customer and
configured in preparation for activation
Activation The process of starting the software execution or
putting in place triggers that will execute the
software at an appropriate time
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Processes
De-Activation In many systems this is required prior to
adaptation or reconfiguration where a piece of
software must be passivated and rendered non-
invocable the inverse of activation
Update The process of changing a piece of installed
software usually triggered by the release of a new
version by the developers
Special case of installation de-activation and
re-activation
De-Installation Removing the deployed software from the
machine on which it was deployed
Obsolence (De-Release) No longer supported by developersS
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Deployment Issues
Change management introducing hardware
and software changes
Dependencies management among software
components
Large-scale content distribution network
reliability
Interoperability of heterogeneous platforms
Deployment coordination and customization
big-bang or incremental
Internet integration
Security
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Deployment Challenges
Mobile applications Heterogeneity and number of the devices
Intermittent network connections
The lack of centralized control
Personal owned
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Maintenance
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Definition
The modification of a software product after
delivery to correct faults, to improve performance
or other attributes, or to adapt the product to a
modified environment (IEEE)
The modification of a software product after
delivery to correct faults, to improve performance
or other attributes (ISO/IEC)
The software product undergoes modification to
code and associated documentation due to a
problem or the need for improvement. The
objective is to modify the existing software
product while preserving its integrity
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ExamplesS
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Y2K many, many systems had to be updated
language analyzers (find where changes need to
be made)
Anti-Virus Software don't usually have to update software, but must
send virus definitions
Web-based applications 73% of total cost of e-commerce used to re-
design the website after its first
implementation
Examples
Windows NT 30 million LOC added within 6 years
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Growth of Windows NT
0
5
10
15
20
25
30
35
1992 1993 1994 1995 1996 1997 1998 1999 2000
Year
Lin
es
of
Co
de
(m
illi
on
s)
WINDOWS NT 3.51
WINDOWS NT 3.1
WINDOWS NT 3.5
WINDOWS NT 4.0
WINDOWS 2000
Types
Adaptive changes in the software environment (DBMS, OS)
Perfective new user requirements
Corrective diagnosing and fixing errors
Preventive prevent problem in the futures (increasing
software maintainability and reliability)
Facts: 75% on adaptive and perfective; 21% on
corrective; 4% on preventive
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Processes
Depending on the types of software being
maintained, the development processes used in
an organization and people involved in the
process
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Change
requestsImpact
analysis
Release
planning
Change
implementation
System
release
Perfective
maintenanceAdaptive
maintenance
Corrective
maintenance
Difficulties
Factors adversely effect maintenance Lack of models or ignorance of available models
(73%)
Lack of documentation (67.6%)
Lack of time to update existing documentation
(54.1%)
Other factors (1994 study) Quality of original application
Documentation quality
Rotation of
maintenance people
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Difficulties
More factors (Yip ’95 study) Lack of human resources
Different programming styles conflict
Lack of documentation and tools
Bad maintenance management
Documentation policy
Turnover
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Maintenance Cost Factors
Team stability Maintenance costs are reduced if the same staff
are involved with them for some time
Contractual responsibility The developers of a system may have no
contractual responsibility for maintenance so there
is no incentive to design for future change
Staff skills Maintenance staff are often inexperienced and
have limited domain knowledge
Program age and structure As programs age, their structure is degraded and
they become harder to understand and change
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Evolution
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Evolution
What is evolution ??
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Definition
Changing a software product after delivery to
adapt such system to the ever-changing user
requirements and operating environment the
system operates in or address a problem or
activity of a real world
Software maintenance bug fixing or error
correction
Software evolution adaptive and perfective
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Software Change
Software change is inevitable New requirements emerge when the software is
used
The business environment changes
Errors must be repaired
New computers and equipment is added to the
system
The performance or reliability of the system may
have to be improved
A key problem for all organizations is
implementing and managing change to their
existing software systems
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Urgency
Organisations have huge investments in their
software systems - they are critical business
assets
To maintain the value of these assets to the
business, they must be changed and updated
The majority of the software budget in large
companies is devoted to changing and evolving
existing software rather than developing new
software
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Lehman’s LawS
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Law Description
Continuing
change
A program that is used in a real-world environment must necessarily
change, or else become progressively less useful in that environment.
Increasing
complexity
As an evolving program changes, its structure tends to become more
complex. Extra resources must be devoted to preserving and simplifying
the structure.
Large program
evolution
Program evolution is a self-regulating process. System attributes such as
size, time between releases, and the number of reported errors is
approximately invariant for each system release.
Organizational
stability
Over a program’s lifetime, its rate of development is approximately
constant and independent of the resources devoted to system
development.
Conservation of
familiarity
Over the lifetime of a system, the incremental change in each release is
approximately constant.
Continuing
growth
The functionality offered by systems has to continually increase to maintain
user satisfaction.
Declining quality The quality of systems will decline unless they are modified to reflect
changes in their operational environment.
Feedback system Evolution processes incorporate multi-agent, multi-loop feedback systems
and you have to treat them as feedback systems to achieve significant
product improvement.
Stage Model : Software Life CycleS
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Initial development
Evolution
first running versionevolution changes
Servicing
code decay
servicing patches
Close-down
Phase-out
servicing discontinued
Switch-off
Versioned Stage ModelS
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Close-down Version 1
Initial development
Close-down Version 2
Phase-out Version 2
Phase-out Version 1
Servicing Version 1
Evolution Version 1
evolution changes
Evolution Version . . .
Evolution Version 2
evolution of new version
evolution of new version
evolution changes
servicing patches
Servicing Version 2
servicing patches
first running version
Initial Development
Developing the first version
System architecture proposed even with some
lack features
System knowledge acquired: application domain,
user requirements, data formats, algorithms,
operating environment, etc. crucial for the
evolution
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Evolution
The stage in a software system’s life cycle where
it is in operational use and is evolving as new
requirements are proposed and implemented in
the system
The first version already released successfully Successful in the marketplace
User demand is strong
Revenue streams are buoyant
The organization is supportive
ROI is excellent
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Evolution : ROIS
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Evolution
Adapts the application to the ever-changing user
and operating environment
Adds new features
Corrects mistakes and misunderstandings
Responds to both developer and user learning
Program usually grows during evolution
Both software architecture and software team
knowledge make evolution possible
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Servicing
Software maturity no longer evolvable
The software remains useful but the only
changes made are those required to keep it
operational i.e. bug fixes and changes to reflect
changes in the software’s environment small
tactical change
No new functionality is added
Code decay loss of system knowledge due to
the loss of key personnel system goes to
servicing
Transition from evolution is irreversible
technical and knowledge problems must be
addressed
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Phase-out and Close-down
Phase-out no more servicing is being undertaken
system still may be in production/use
Close-down the software use is disconnected
towards replacement
an ‘exit strategy’ is needed : changing to another system requires retraining
what to do with long-lived data?
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Next
Software Engineering Advanced Research and
Development
Software Project Management
Information Technology Industrial Management
Software Quality Assurance
“As long as we live in this digital era, we are needed”
Who are we ?
We are IT Engineer
Whatever your majority !
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Terimakasih v^^
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