VBM - Vision Based Methodology™

Activity 9: Constructing the System

A Word about Object Oriented Programming

Finally, bottom-up programming with a new name and an even higher level of rigor! Object oriented programming represents a new "paradigm" in creating computer software. Classes are defined as stand alone things which react to external events and communicate with other Classes. These concepts are very similar to the approach taken when creating "shared routines" and common reusable algorithms. OOP has formalized these ideas and created a disciplined approach which is centered on maximum programming component reusability.

OOP Benefits:

• Easier program maintenance and functional upgrading is realized after the application development is complete.
• Although substantial learning curves do exist, and time and effort are required to create the initial framework (library) of reusable classes (modules), the pay back becomes exponential when the "building block" classes can be rapidly assembled to create new applications software.
• OOP assists in creating complex, reusable new objects (classes) to handle such things as GUI (Graphical User Interfacing), distributed database accessing, network communication linking, or standardized security checking which are then available for inclusion (inheritance) in new application programs. These complexities then become less of a burden on the individual programmers.
• Classes have the potential to become business oriented technology "assets".

OO Construction Approach:

1. First, examine the Classes (pre-written modules) which currently exist as a part of the framework (Class library) which came with the selected OOP language to determine the possible utilization opportunities.
2. Next, based on the application requirements, develop a framework (library) of custom written classes (modules) to be reused throughout the programming effort.
3. Then fully review and test all reusable classes before allowing them to be inherited by the application programs.
4. When finished, create the higher level application programs (super classes) with an eye toward reusability at this level also.
5. Last, review, test, and assemble the system components using the same principals discussed for all of the other coding techniques.
6. Conduct "White-Box" testing to insure that the internal processing of each Class is functioning correctly.
7. Conduct "Black-Box" testing to insure that all message processing between classes is functioning correctly.
8. Review each targeted reusable class for the proper level of generalization in order to facilitate its use by other projects.