The Software Package Development Methodology (SPDM) is a methodology for developing complex and customizable software packages supporting business processes, especially Enterprise Resource Planning (ERP) software. Two approaches are applied by this chapter. First SPDM will be compared to a method engineering framework. Method engineering is a discipline to construct new methods from parts of existing methods taking into account situational factors. The second approach is the analysis of the results of a questionnaire, asking users of SPDM their opinion on several issues concerning problems and quality of SPDM. The conclusions, after applying both approaches, are quite similar and some recommendations are made for future research.