In this paper, a Max-Plus algebra model via the Timed Petri Net (TPN) model for a class of robotic assembly cell is developed. The paper describes the basic concepts of max-plus algebra which can be used for online control of manufacturing systems. The method presented in this paper, first model the given robotic assembly cell problem of assembling two parts using a timed Petri nets and generates a firing sequence for it. The detailed operational sequence for the assembly cell is explained and a reachability matrix for the Petri net model is also given. The complete cycle of the timing diagram required for the max-plus algebra model is presented by plotting a graph between location number and time. Based on the generated firing sequence of the petri net model, a max-plus algebra model is formulated. The formulated max-plus algebra model can be used for online computation and to schedule the operations of robotic assembly cell.