Estimating Costs and Allocating Resources

I feel like the most challenging thing about estimating activity durations and resource costs is the actual estimation. It takes a great deal of research and study in order to calculate the costs and timing of a project and sometimes the best preparation is experience. Calculating cost can be tricky in that there is always the possibility for unexpected obstacles to incur unexpected cost. With the right experience a project manager will be able to calculate any surprise costs, within reason. Time estimation comes with its own challenges. Like in cost estimation, there are possibilities that timing issues may arise during a project. However, I feel like these time issues are far more damaging to the health of a project than any cost issues that may arise. Every circumstance is different but unexpected time obstacles can throw off the entire chronology of a project and put the release at risk. I feel that estimating the duration of each activity is the riskiest part of the estimation process and should be handled with great care.