Although your request to "put together some sort of a amethodology that you can meet your customer requirements" is not a new request, it is a very difficult one to answer. many methodologies exist already.  You can spot more than one thousand methodolgies in the literature. The difficulties stem from the fact that methdology is highly dependent on the development team, the stakeholder, and the development environment.  A successful IS (which is a Human Activity System) methodology in England or USA may not work in South Africa or in China. Generally, you can devlop your own by using some of the exisiting ones.  A methodology as Soft System Methodology (SSM Checkland) is very powerful in the early stages of problem definitions and CATWE analysis. Structured Methodolgy can be used to anlyze and identify systems processing function and business needs. You can take the data anlysis models to be based on the best practice of Information Engineering with its various development schemes. When it comes to the cultural issues of nformation system analysis, a methodolgy like ETHICS is worth the consideration, toghether with the Multiview methdlogy . Into the technical side of the design phase there are Yourdon, Merese and number of other Object Oriented Analysis.  Please, visit www.geocities.com/analyst_corner/analyst.html where you can find useful links to methodologies search, and more that one hundred reference on methdologies.  You can also find a reference for an article in South Africa by " Michael Khan, 1999" for requireents analysis.

Good luck  

Dr. Samir Mostafa