Five worlds:Not all software development is the

same

Matthew HeusserExcelon Development – xndev.com - matt@xndev.comPresented to CS 611 at GVSU, 4/6/2005

Introduction

• This lecture is based on the work of Joel Spolsky:– http://www.joelonsoftware.com/articles/FiveWorlds.html

• And the context-driven school of software testing

Prescriptive Models …

• “When you read the latest book about Extreme Programming, or one of Steve McConnell's excellent books, or Joel on Software, or Software Development magazine, you see a lot of claims about how to do software development, but you hardly ever see any mention of what kind of development they're talking about, which is unfortunate, because sometimes you need to do things differently in different worlds.”– Spolsky, “Five Worlds”

Five Worlds

• Commercial– Shrinkwrap– Consultingware – Web-Based (e-commerce or ASP)

• Internal

• Embedded

• Games

• Throwaway

Shrinkwrap

• Build once, sell millions

• Relatively low cost per seat

• Individual customers have little say

• You need an ‘abstractor’ to represent the customer

ConsultingWare

• Think CRM or ERP

• Expensive out of the box – Plus extra $$ for customization

Web-Based

• E-Bay

• Amazon

• SalesForce.com

• Deploy-Once

Internal

• Develop for use

• One customer or a customer group

• You can usually ‘lock down’ the OS, Browser, Database, etc, etc.

Embedded

• Siemens/Rapistan

• Smith’s Aerospace

Games

• Versions

Throwaway

• Scripts

• Spikes

Conclusion

• “Most things in software development are the same no matter what kind of project you're working on, but not everything. When somebody tells you about methodology, think about how it applies to the work you're doing. Think about where the person is coming from.” - Spolsky