1. SYSTEM ANALYSIS & DESIGN
PHASE 4
SYSTEM ANALYSIS & DESIGN
SYSTEM IMPLEMENTATION
APPLICATION DEVELOPEMENT
DOCUMENTATION
Ritwik Raj Singh

2. SYSTEM IMPLEMENTATION
Systems implementation is the process of :
Defining how the information system should be built (i.e., physical system design).
Ensuring that the information system is operational and used.
Ensuring that the information system meets quality standard (i.e., quality assurance).

3. Design Strategy
DOCUMENTATION REVIEW
DESIGN
CODE
TEST
Documentation

4. Application Development
Application developement is the process of constructing the program and code modules that are the building blocks of the information system.
Following steps are required for application developement
Documentation review and application design
Coding
Testing

5. Documentation review and application design
Design documentation is the set of documents that accompany a design that explains both the details of the design and the decisions that went into the design.
Among the five phases of the system development life cycle (SDLC), coding and testing usually requires about 65% of the time.
Users of the design need to understand the interface and functionality of the design.
Maintainers need to understand the details and the reason for those details in order to be able to change the design or come up with new designs.
The design specification of a component comprises an interface specification and a description of the functionality.

6. Documentation review and application design
The design specification must be done before the component is implemented.
Used for quality assurance to detect and avoid problems as early as possible.
Quality assurance can detect
Inaccurate requirements
Design or coding errors
Faulty documentation
Ineffective testing
Insufficient security
CMM i.e., Compatibility Maturity Model for Softwere, is important for judging the maturity of the software processes of an organization and for identifying the key practices that are required to increase the maturity of these processes.

7. Coding
It is a process of turning program logic into specific instructions that can be executed by the computer system.
Many programming languages exist
Visual C++
Access Basic
Visual Basic
SQL
HTML
Java etc..
More than one programming language may be required to implement the featuresof the system. So a language that is portable to different computer and operating systems should be selected.

8. Coding
Select a programming environment for which most tools are available.
Select a language that is experienced by most of the programmers of the organization.
Principles of good programming:
Keep coding style simple, so it can easily comprehended and edited, if necessary.
Keep codes structured. For example: use suitable indentation for Do-While, If-Then-Else, and Case loops.
Use good comments to describe the purpose of a coding block.

9. Testing
Testing is necessary to ensure that all programs function correctly.
First step is to detect syntax errors and obtain a clean compilation.
Next step is to eliminate logical errors.
Final step is testing of unit, link, and systems testing.

10. Unit Testing Involves an individual program.
Objective is to identify and eliminate execution errors and any remaining logic errors.
Stub testing is a technique of using stubs to represent entry or exit points that will be
linked later to another program or data file.

11. Link Testing/Integration Testing
Involves two or more programs that depend on each other.
Also called string testing, series testing, or integration testing.
Link testing ensures that the job streams are correct.
Test data is necessary to simulate actual conditions and test the interface between programs.

12. System Testing
Involves the entire information system and includes all typical processing situations.
Requires users to verify all processing options and outputs.
Uses live data.
Involves a final test of all programs.
Ensures that proper documentation is ready.
Confirms that the system can handle predicted data volumes in a timely and efficient manner.
Verifies that all system components work correctly.

13. Documentation Explains the system and helps people interact with it.
Types of documentation
Program documentation
System documentation
Operation documentation
User documentation

14. Program Documentation
Begins in the systems analysis phase and continues during systems implementation.
Includes process descriptions and report layouts.
Programmers provide documentation with comments that make it easier to understand and maintain the program.
An analyst must verify that program documentation is accurate and complete.

15. System Documentation
System documentation describes the system’s functions and how they are implemented.
Most system documentation is prepared during the systems analysis and systems design phases.
Documentation consists of
Data dictionary entries
Data flow diagrams
Screen layouts
Source documents
Initial systems request

16. Operations Documentation
Typically includes the following items:
System overview
Source document description, with samples
Menu and data entry screens
Reports that are available, with samples
Security and audit trail information
Responsibility for input, output, processing
Procedures for handling changes/problems
Examples of exceptions and error situations
Frequently asked questions (FAQ)
Explanation of Help & updating the manual

17. Operations Documentation
Written documentation material often is provided in a user manual.
Analysts prepare the material and users review it and participate in developing the manual.
Online documentation can empower users and reduce the need for direct IS support
Context-sensitive Help
Interactive tutorials
Hints and tips
Hypertext
On-screen demos