Seasonal availability of supply and demand market of biomass is one of the challenges for its energy conversion. A suitable production planning approach is required to consider the dynamic characteristic. This study aims to identify the production rate, inventory and supply flow of biomass by integrating Pinch Analysis and mathematical model. Storage to overcome the deficits of biomass supply at the following time interval is also identified. The demonstrated case study suggested a fix production rate of 22,000 GJ/month and adapted to 6,167 GJ/month after the pinch point to meet the fluctuating demand. The required inventory is also suggested. For example, 3,167 GJ of product (bio-oil) inventory on Month 4 to meet the following demand, and with 3,764.1 GJ (301 t) of biomass as storage to overcome the supply deficit (fluctuated) in the following month. The mathematical approach optimises the biomass network flow (allocation) at each time intervals (Month). Emission and transporting cost, as well as the energy content of the biomass resources, are considered. Pinch Analysis serves as an effective tool in providing a starting solution dealing with fluctuating supply and demand for further planning.