1. FORMAL SYSTEM DEVELOPMENT METHODOLOGIES
Lecture-3

2. FORMAL SYSTEM DEVELOPMENT METHODOLOGIES
The steps of SDLC are used in many development methodologies.
These methodologies are called Formal SD methodologies.
Each step of SDLC is divided into many activities or phases.
In these methodologies formal reports are submitted at the end of each phase.
These reports show the status of the development process and provides a checkpoint.
These methodologies are used for developing large systems.

3. 1. STRUCTURED SYSTEMS ANALYSIS & DESIGN
Used in 1970s by many organizations.
Structured Analysis is a technique in which Data Flow Diagrams (DFD) are used instead of Flowcharts which show execution sequence of a program.
DFD help to understand logical system or what the system is doing.
This technique help the analyst to define the user requirements more
accurately, because he does not focus on underlying technology.

4. Structured Design is a technique in which Computer programs are developed in Top-Down hierarchy of modules. Each module is a code segment which performs single functionality. Structure charts can be used to describe these programs. Easily written and tested, and easily modified.

5. A Phased Approach To system Development
ILLUSTRATION
A Phased Approach To system Development
Implementation
Operation
Systems Analysis
Systems Design
Programming
String Testing
Post-implementation Review
Preliminary Survey
Feasibility Study
Preliminary Design
Detailed Specification
System Testing
Equipment Installation
Conversion
Training

6. 2. CASE Tools
Computer Aided Software Engineering is a technique which uses several tools to automate the tasks of many software development activities.
For example: drawing DFDs or Flowcharts, maintaining records of data files, inputs and outputs, maintaining system documentation.
CASE tools increase the productivity of project personnel.
CASE tools improve the quality of new system and documentation.

7. 3. PROTOTYPING
It is technique in which a working model of the required system is developed called Prototype. This model performs the major functions of the required system which are lacking details. This model is provided to the users for better understanding and explaining their requirements. It is developed by experienced system analysts. REQUIREMENTS This technique is used for small systems such as DSS. High-level software development tools are required such as report generators, display screen generators, 4th-generation language and RDBMS.

8. An Approach To Prototyping
ILLUSTRATION
Analysis. Create an incomplete paper model of the system based on preliminary interviews with users.
Database Development. Create a test database for use in prototyping. Using a RDBMS, the prototype can be easily changes.
Menu Development. Describe the menus that will guide the user of the system. A menu identifies functions to be performed.
Function Development. Describe the functional modules that execute the processes in the system. These may include, e.g. data entry & report generation.
Prototype Iteration. Using software development tools, create each module. This produces a working model of the system that a user can easily modify. Make changes to the prototype until the user is satisfied.
Detailed Specifications. Refine the system as necessary to make it efficient in creating a production system. Complete the documentation for the system.

9. AUDITOR INVOLVEMENT IN SYSTEM DESIGN
Auditor can contribute a lot tot the process of developing an accounting system.
Internal auditors or independent auditor can participate in process.
Mostly, auditors are involved in the system design phase. They review the detail specifications and give suggestions.
They are involved in the testing and conversion of implementation phase.
An auditor’s work is concerned with auditability and controls of the system.

10. AUDITOR’S ROLE IN THE DEVELOPMENT PROCESS
ILLUSTRATION
AUDITOR’S ROLE IN THE DEVELOPMENT PROCESS
System Analysis Phase
Provide audit reports on systems being examined to the study team.
System design Phase
Review the proposed design:-
1. Reports. Identify information needed in reports for control & auditability.
2. Processing steps. Suggest control procedures.
3. Equipment Selection. Ensure that those selected conform to existing company policies.
4. Data files. Determine that data will be accurate & complete, and will provide the ability to
audit the system.
System Implementation Phase
adequacy of test data and test results are reviewed. Conversion plans are reviewed to ensure that
accurate data is maintained while shifting to new system.
System Operation Phase
Assess the adequacy of internal controls in the operational system.

11. The Audit Trial
Auditors review a system to decide whether it provides necessary information to conduct an audit.
This information is called audit trial and it is included in the reports produced by the system.
Audit trial is important because it enables an auditor to evaluate the accuracy of financial statement amounts and to determine the sources of errors in summary reports.

12. Controls
Controls are used for examining the financial statements.
Controls are included in the system on the suggestions of auditor.
Controls help the system produce accurate and reliable reports.
The accounting records stored by such a system are very secure.

13. THANK YOU