To enable software designers to achieve a higher quality for their design, a better insight into quality predictions for their design choices, test plans improvement using Simulated Defect Removal Cost Savings model is offered. In this paper we propose a model which enables to minimize the cost of switching between test plan alternatives, when the current choice cannot fulfill the quality constraints. The defect containment measure is traditionally used to provide Insight into project success (or lack thereof) at capturing defects early in the project life cycle, i.e., the time when defect repair costs are at their minimum. We offered a simulation method with which it is possible to assist the test manager in evaluating test plan alternatives and adjusting test process improvement decisions in a systematic manner. Using raw defect containment data and deriving Quantitative Defect Management (QDM) measures early in the development life cycle provides opportunities for a project to Identify Issues in defect capture before costs spiral Out of control and schedule delays ensue. We simulated two scenarios (a standard quality assurance activities plan and comprehensive quality assurance activities plan) and calculated test process improvement potential according to derived QDM measures.