Flowshop Scheduling Problem (FSP) is a common but not trivial problem in manufacturing scheduling. Lower bound (LB) measures can provide a reasonable estimation considering makespan minimization. This paper deals with an analysis of a LB measure comparing with the CDS heuristic and the optimal solution of FSP. Performed simulations varying the number of jobs (N) and machines (M) with processing times following uniform and exponential distributions show that the discrepancies between the solutions tend to increase until N and decrease for N greater than M, with largest discrepancy observed for N equal M. The divergences tend to be larger when greater variability on processing times is considered.