In the proposed study, we have strived to study the inventory models with the phenomenon of two-warehouse, manufacturer-retailer cooperation and considered the factors of Weibull distribution amelioration and deterioration, multiple deliveries, time dependent partial backlogging in an inflationary environment. Since these phenomena are not uncommon in real life, we incorporate them in our problem development. Manufacturer’s has two storage facilities in which one is the own warehouse (OW) and another is a rented warehouse (RW) and assume that the holding cost in RW is higher than that in OW. The manufacturer’s stores goods in OW before RW, but clears the stocks in RW before OW. This study takes into account of inflation. The model is illustrated for a finite planning horizon. The optimization framework is presented to derive the optimal replenishment policy that minimizes the total present value cost. Numerical examples and sensitivity analysis are given to illustrate the theory of the integrated inventory system.The system is solved using the mathematical software MATLAB 7.0.1.