Faculty of Computers and Information
Software Engineering Program (JMSE)
Software
Dr. Lamia Abo Zaid
Evolution ﻟﻣﯾﺎء أﺑوزﯾد. د
LECTURE 7 : EVOLUTION AND MAINTENANCE MODELS 1
Based on slides by © Tripathy & Naik
Software Evolution : TOC
1. Introduction to Software Evolution
2. Taxonomy of Software Maintenance and Evolution
3. Evolution and Maintenance Models
4. Reuse and Domain Engineering
5. Program Comprehension
6. Impact Analysis
7. Refactoring
8. Reengineering
9. Legacy Information Systems
LECTURE 7 : EVOLUTION AND MAINTENANCE MODELS 2
Maintenance as part of the SDLC
Software maintenance has unique characteristics:
Software Maintenance Life Cycle (SMLC)
Constraints of an existing system
Shorter time frame
Available test data
LECTURE 7 : EVOLUTION AND MAINTENANCE MODELS 3
Why Do We Need Models to Manage &
Execute Software Maintenance Activities?
Change, Evolution, and system configuration complicate maintenance activities.
The software product released to a customer is in the form of executable code,
whereas the corresponding “product” within the supplier organization is source code.
Thus, strict control must be kept, otherwise exact source code representation of a
particular executable version may not exist.
Three maintenance models will be explained:
1. Reuse old
2. Simple Staged relatively new
3. Change Mini-cycle still in research
LECTURE 7 : EVOLUTION AND MAINTENANCE MODELS 4
Change Mini-Cycle Model
Software change is a process that may
introduce new requirements or alter the
software system if requirements are not
correctly implemented. Yau et al (1978)
introduced the change mini-cycle evolutionary
model to capture this and revisited by other
researchers, namely, Bennet et al. (2000) and
Mens (2008).
LECTURE 7 : EVOLUTION AND MAINTENANCE MODELS 5
Change Mini-Cycle Model
mini-cycle model consists of five major phases:
1. Change Request (CR): defect report or
enhancement request
2. Analyze and plan change: Program comprehension,
Impact analysis and ripple effect
3. Implement change: change propagation
4. Verify and validate: code review, regression testing,
and execution of new tests
5. Documentation change.
LECTURE 7 : EVOLUTION AND MAINTENANCE MODELS 6
Software Maintenance Standard
IEEE and ISO have both addressed s/w maintenance processes.
IEEE/EIA 1219 considers maintenance as a fundamental life cycle process , it
organizes the maintenance process in seven activities :
problem identification, analysis, design, implementation, system test, acceptance
test and delivery.
ISO/IEC 14764 describes s/w maintenance as an iterative process for
managing and executing software maintenance activities, which are :
process implementation, problem and modification analysis, modification
implementation, maintenance review/acceptance, migration and retirement.
LECTURE 7 : EVOLUTION AND MAINTENANCE MODELS 7
IEEE/EIA 1219 Maintenance Process
The standard focuses on a seven-phases
Each of the seven activities has five associated attributes as follows:
Activity definition: This refers to the implementation process of
the activity.
Input: This refers to the items that are required as input to the
activity.
Output: This refers to the items that are produced by the activity.
Control: This refers to those items that provide control over the
activity.
Metrics: This refers to the items that are measured during the
execution of the activity.
LECTURE 7 : EVOLUTION AND MAINTENANCE MODELS 8
IEEE/EIA 1219 Maintenance Process
•The change request (CR) is submitted in
the form of a modification request (MR)
for a correction or for an enhancement.
MR & CR are used interchangeably.
• Activities include:
1. reject or accept the MR,
2. identify and estimate the resources
needed to change the system
3. put the MR in a batch of changes
scheduled for implementation.
LECTURE 7 : EVOLUTION AND MAINTENANCE MODELS 9
IEEE/EIA 1219 Maintenance Process
Analysis
LECTURE 7 : EVOLUTION AND MAINTENANCE MODELS 10
IEEE/EIA 1219 Maintenance Process
Design
LECTURE 7 : EVOLUTION AND MAINTENANCE MODELS 11
IEEE/EIA 1219 Maintenance Process
Implementation
LECTURE 7 : EVOLUTION AND MAINTENANCE MODELS 12
IEEE/EIA 1219 Maintenance Process
System test
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IEEE/EIA 1219 Maintenance Process
Acceptance test
LECTURE 7 : EVOLUTION AND MAINTENANCE MODELS 14
IEEE/EIA 1219 Maintenance Process
Delivery
LECTURE 7 : EVOLUTION AND MAINTENANCE MODELS 15
Questions
LECTURE 7 : EVOLUTION AND MAINTENANCE MODELS 16
Readings
Chapter 3 : 3.4, 3.5, 3.6
LECTURE 7 : EVOLUTION AND MAINTENANCE MODELS 17
