1. Problem Solving Methodology
PSM
Problem Solving Methodology

2. PSM Overview Analysis Design Development Evaluation
Solution Requirements
Solution Design
Manipulation (Coding)
Strategy
Solution Scope
Evaluation Criteria
Validation
Reporting
Solution Constraints
Testing
Documentation

3. Analysis Stage - Overview
Analysis typically answers the 'what questions'
What will solve a problem, given particular circumstances?
What benefits will the solution bring to the user?
Analysis
Solution Requirements
Solution Scope
Solution Constraints

4. Analysis Stage - Tools
Tools to assist in determining the solution requirements include
context diagrams (level 0 DFD)
data flow diagrams and
use case diagrams

5. Analysis Stage – Requirements
Determining the solution requirements.
What information does the solution have to provide?
What data is needed to produce the information?
What functions does the solution have to provide?
These requirements can be classified as being:
functional, namely what the solution is required to do, and
non-functional, which describes the attributes the solution should possess, such as
user-friendliness,
reliability,
portability,
robustness,
maintainability.

6. Analysis Stage - Constraints
Identifying the constraints on the solution.
What conditions need to be considered when designing a solution?
Typical constraints include
cost,
speed of processing,
requirements of users,
legal requirements,
security,
compatibility,
level of expertise,
capacity,
availability of equipment.

7. Analysis Stage - Scope Determining the scope of the solution.
What can the solution do?
What can't the solution do?
What are the benefits of the solution to the user?
The scope states the boundaries or parameters of the solution. Benefits can be stated in terms of their efficiency and effectiveness.

8. Design Stage - Overview
Planning how the solution will function
The appearance of the resulting information.
The solution design typically involves identifying:
What specific data is required
How the data will be named, structured, validated and manipulated.
Evaluation Criteria
Design
Solution Design
Evaluation Criteria

9. Design Stage – Design Tools
Typical design tools for this purpose include
data dictionaries and data structure diagrams,
input-process-output (IPO) charts,
flowcharts,
Pseudo-code
Object descriptions.

10. Development Stage - Overview
Electronically manipulating (or coding) data to 'build' or create the solution following initial designs.
Validation and Testing
Where appropriate, internal documentation is also written, which documents the functioning of the solution.
Writing documentation to support the use of the solution.
Manipulation (Coding)
Validation
Testing
Documentation

11. Development Stage - Validation
Validation to check for the reasonableness of data being input.
Validation can be both manual and electronic.
Proofreading is a manual technique and it occurs when data is entered directly into the solution and remains fixed, such as in a web page.
When the validation process has been built into the solution (electronic technique), then its effectiveness is determined through the testing activity.

12. Development Stage - Testing
Testing whether the solution does what it was intended to do. This activity typically involves:
establishing what tests will be conducted
determining what test data, if any, will be used
determining expected results
conducting the test
recording the actual results
correcting any identified errors.

13. Development Stage - Documentation
Will involve both internal and external documentation
Internal is use to help other programmers understand your code
External documents are intended for the user typically in the form of USER MANUALS.

14. Evaluation Stage
Strategy involved to effectively evaluate the solution/product
Reporting on how the well the solution met all requirements of the user.
Evaluation
Strategy
Reporting

15. Evaluation Stage – Strategy
Determining a strategy for finding out the extent to which the solution meets the required needs. Typically this would include
Specifying a timeline
Outlining what data will be collected and by what methods and techniques, and
How the data relates to the criteria, which were developed in the designing stage.
More than just asking user a list of questions…

16. Evaluation Stage – Reporting
Reporting on the extent to which the solution meets the requirements of the user.
It usually takes place after the solution has been used by the user/client and is based on the criteria developed in the designing stage.

17. Scope How much should the solution be able to achieve?
The scope of a project defines:
How big it is going to be.
How broadly it will search for causes and possible solutions to the problem.
What should the solution be able do?
What limitations are acceptable in the solution?
What should be the benefits of the solution to the user?

18. Scope
The scope states the boundaries or parameters of the solution in terms of their efficiency and effectiveness.
Will it be a Narrow Scope? A Broad Scope?
Entails a lot of changes and lots of work
Project tend to be bigger and slower.
Requires more investigation of different factors before deciding on a solution.
Will affect more parts of the information system.
Makes fewer assumptions about the cause and solution of a problem.
More likely to accurately identify the true cause of a problem and fix the problem effectively.
More tightly limits the changes required.
to be smaller and quicker to finish.
It makes more assumptions about the true cause and best solution of the problem.
Wrong assumptions can prevent solving of problem (thus terminates)

19. Scope - Example
The requirement is a faster internet connection is needed.
one could simply increase bandwidth (a narrow scope, because it assumes inadequate bandwidth is the cause of the problem)
one could investigate all of one's internet hardware and software (a broad scope) before designing a solution.

20. Constraints