摘要： As pointed out in several analyses, Stand-Alone Photovoltaic systems may be a relevant option for rural electrification in Developing Countries. In this context, Micro and Small Enterprises which supply customized Stand-Alone Photovoltaic systems play a pivotal role in the last-mile-distribution of this technology. Nevertheless, a number of issues limit the development of these enterprises curbing also potential spinoff benefits. A common business bottleneck is the lack of technical skills since usually few people have the expertise to design and formulate estimates for customers. The long-term solution to tackle this issue implies the implementation of a capacity building process, but this solution rarely matches with time-to-market urgency of local enterprises. Therefore, we propose in this study a simple, but general methodology which can be used to set up Design Support Tools for Micro and Small Enterprises that supply Stand-Alone Photovoltaic systems in rural areas of Developing Countries. After a brief review of the techniques and commercial software available to design the targeted technology, we describe the methodology highlighting the structure, the sizing equations and the main features that should be considered in developing a Design Support Tool. Then, we apply the methodology to set up a tool for use in Uganda and we compare the results with two commercial codes (NSolVx and HOMER). The results show that the implemented Design Support Tool develops correct system designs and presents some advantages for being disseminated in rural areas. Indeed it supports the user in providing the input data, selecting the main system components and delivering estimates to customers.