Rapid Application Development / Advanced Excel Development

VBA Best Practice

There is a lot of information floating around about how to get various things done in VBA, how to make the best use, or sometimes just the most use of VBA and Excel.
This section aims to add an element of Quality and Best Practices. These are just general guidelines, a professional developer will always assess the options and make the appropriate choice in their specific situation.
These suggestions are specific to Excel VBA in commercial settings, many will not translate to other technologies or other settings.

VBA Best Practice Series

Development Process

• Systems Development lifecycle
• (these don't all flow neatly like a waterfall, but are the main elements of the process of delivering working, fit for purpose software)
• Requirements - understanding what the system should do, this will change as the project progresses - be ready for that
• Analysis - sorting through the requirements, understanding the implications, dealing with conflicts
• Logical Design - a theoretical design, perhaps on paper of the sort of things the system will need to satisfy the requirements. This element drives the next one
• Technology Choice - based on the logical design, what is the most appropriate technology to implement the system? This step is so often missed.
• Physical Design - converting the logical design into the actual technology - eg if the system needs a relational database or an OLAP database, this stage defines the table structure.
• Construction - actually building the system - involves going back through all the stuff as new requirements are identified etc.
• Test - each component should be tested (unit testing) as soon as possible and throughout development, then they should be tested together (integration testing). System testing aims to ensure the model does what the developers think it should. User Acceptance testing aims to check it does what the users need, (at this stage that should be clear and well known to the developers).
• Release - making the system available, live to the users, may include deploying the system to servers and/or desktops.
• Maintain - keep the system working, adapt to changes in requirements
• In some shape or form.
• Understanding the requirements is critical and difficult
• Some sort of structured approach is useful
• Build a library of useful code and references

Spreadsheet Development Lifecycle

• Oh! I need a model" - clickety-click, reasonableness check, release, (Test & Maintain in live environment).