SSD Managing Projects and
Methodologies
Systems Methodologies
explain the purpose of applying a methodology to the solution
of systems problems;
discuss how methodologies have evolved in line with changing
technologies and discuss the roles of participants in their
application;
assess the application of a range of methodologies including
traditional, iterative and Agile methods:
− Waterfall;
− RAD;
− DSDM;
− SCRUM; and
− XP;
examine the application of methodologies in specific
situations;
explain stages, rules, tools and techniques associated with
methodologies; and
examine the role of prototyping in the development process.
explain the basic concepts of UML and apply some simple
modelling techniques;
Applying Methodologies
Building software is a long and complicated process with many independent tasks and
large teams to manage. This process is simplified by applying a methodology which;
describes the formal approach that will be used to manage the development of a new
software system;
provide a framework incorporating the knowledge gleamed from years of software
development;
split the process into a set of phases;
follow the stages in a specified order to create a development lifecycle;
details the activities to complete within each stage supported by guidelines,
principles, tools, techniques and documentation;
helps improve the quality of the software system and the development process.
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, A wide variety of these methodologies have appeared over the years, evolving and each
with its own strengths and weaknesses. They also vary in philosophy. Depending on the
software and the team, one methodology may suit better than another.
Large and complex systems were rarely built in the 60’s and 70’s, as the projects were
often late, over budget, unreliable and difficult to maintain, and the software being
produced was often outperforming the currently available hardware, resulting in a
software crisis. To address this, the first methodology was developed, the waterfall
method. This was then improved upon by the RAD method, and more recently Agile has
become the norm.
The Waterfall/Traditional Model
This evolved from the construction industry, and the discrete stages of the software
development lifecycle are followed in a sequential fashion from top to bottom with
different personnel involved at each stage. Each stage must be completed with
deliverables before the next stage can begin.
ANALYSIS AND REQUIREMENTS
To find out the requirements of a client, a detailed investigation into the running of the
current system is carried out. This investigation makes use of 4 methods of fact-finding;
1. Examining Existing Documentation: can be helpful when you try to gain some insight
as to how the requirement for a database arose. If the problem relates to the current
system, there should have to be documents associated with that system. By
examining documents, forms, reports, and files associated with the current system,
you can quickly gain some thoughtful concepts out of the system.
2. Interviewing: is the most frequently used, and usually the most useful. We can
interview to collect information from person face-to-face. There can be several
objectives for using interviewing, such as finding out facts, verifying those facts,
clarifying these released facts, generating enthusiasm, getting the end-user involved,
identifying requirements, and gathering ideas and opinions. However, using the
interviewing practice must require proper communication skills for dealing effectively
with people who have different values, priorities, opinions, motivations, and
personalities.
3. Observing the enterprise in action: Observation is one of the most successful fact-
finding techniques carried out for understanding a system. Using this technique, it is
achievable to either participate in or observe a person perform activities to learn
about the system.
4. Questionnaires: special-purpose documents that allow facts to be gathered from a
large number of people while upholding some control over their responses. When
dealing with a large number of listeners or audience, no other fact-finding technique
can tabulate the same facts so efficiently. There are two types of questions that can
be asked in a questionnaire, namely free-format and fixed-format. Free-
format questions offer the respondent greater freedom inputting answers. Fixed-
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, format questions require specific responses from individuals, and for the given
question, the respondent must choose from the available answers.
FEASABILITY OF REQUIREMENTS
Once the requirements have been clearly identified, a feasibility study allows a decision
on whether the project is feasible enough to continue. The study considers several
perspectives; Legal, Social, and Technical. The system’s services, constraints and goals
are established alongside the system users. These are then defined in detail and serve as
the user requirement specification.
SYSTEM AND SOFTWARE DESIGN
The design phase defines how the system will be constructed in order to meet the user
requirements. This process will include;
Storyboards for data capture forms and user interface will be produced;
Queries and reports will be designed;
Validation and verification methods will be specified;
Data structures such as tables and links will be created;
Module and system specifications will be produced;
Data Flow diagrams (DFDs) and Entity Relations Diagrams (ERDs) may be used.
IMPLEMENTATION
At this point the programmers will write, edit, debug and document the program code
using the language that has been chosen, following the design provided by the designers.
TESTING
There are different stages of testing applicable to different stages of development. All
testing must be planned at the design phase to ensure it is actually carried out. During
development, Unit Testing is carried out, which is the process of testing each small
component of the program. The later testing of several components together is
Integration Testing. Testing ensures the system meets the user requirements agreed at
the analysis stage.
MAINTAINANCE
Once a system is complete and in use by the customer, maintenance will take place at
regular intervals, followed by a review, which will eventually result in a new system being
developed. There are three types of maintenance;
Perfective Maintenance - Even though the system runs in a satisfactory manner,
there is still room for improvement.
Adaptive Maintenance - All companies have changing needs. The business may
expand or there may be new hardware developments or changes in legislations.
Corrective Maintenance - Problems often arise after a system has been in use for
some time, even though it has been thoroughly tested and these problems need fixed.
ADVANTAGES OF WATERFALL
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