Farm-household relations represent a central question as related to data collection / processing to provide information on rural development and agricultural-based households income. This issue implies both theoretical and empirical (modelling) facets. In the framework of the SEAMLESS Integrated Project (EU Framework Programme 6), the Farm System Simulator (FSSIM) model was developed. Based on FSSIM a household module is built to take into account farming-household inter-linkages, particularly inflows of extra-farming income by household members, as well as use of (household) family labour, and households (self) consumption of farming outputs. The improvements being developed in the model will allow including issues peculiar of inter-tropical farming systems (FSSIM Africa – provisional title of the new model). Concerning methodological improvements, the last advancements in (Positive) Mathematical Programming as an approach useful to model ex-ante farm-household behaviour under relevant policy scenarios are addressed. The paper includes results of a farm-household survey of Sierra Leone. Results focus on farm-household relations, addressing data collection / processing issues as related to farm-household and village connections.