Integrated Circuits (IC) floorplanning is an important step in the integrated circuit physical design; it influences the area, wire-length, delay etc of an IC. In this paper, Order Based (OB) representation has been proposed for fixed outline floorplan with Simulated Annealing (SA) algorithm. To optimize the IC floorplan, two physical quantities have been considered such as area, and wire-length for hard IP modules. Optimization of the IC floorplan works in two phases. In the first phase, floorplans are constructed by proposed representation without any overlapping among the modules. In the second phase, Simulated Annealing algorithm explores the packing of all modules in floorplan to find better optimal performances i.e. area and wire-length. The Experimental results on Microelectronic Center of North Carolina benchmark circuits show that our proposed representation with SA algorithm performs better for area and wire-length optimization than the other methods. The results are compared with the solutions derived from other algorithms. The significance of this research work is improvement in optimized area and wire-length for modern IC.