A major challenge of Dynamic reconfiguration technique is to maintain Quality of Service, which is meant to reduce application disruption during the system transformation. Dynamic reconfiguration [4] technique involves the ability to change the system's functionality or topology while the system is running. This technique involves safe dynamic reconfiguration such as insertion, removal and replacement of components. Dynamic reconfiguration technique looks very much like traditional control system model of 'sense-plan-act'. Wei li [1] discussed the problem for componentbased software systems. In [1] the authors have defined the spectrum of QoS characteristics, the requirements for QoS characteristics are analyzed and solutions proposed to achieve them. They further classified the prior work based on QoS characteristics and then realized by abstract reconfiguration strategies. First-in-first-out order is important to some applications like Railway Reservation Systems which is not discussed in [1]. The Proposed work concentrates on ensuring the order of requests during reconfiguration. The concept can be proved by simulating it on the online applications to detect the QoS violations. The most important conclusion from our investigation is that the classified QoS Characteristics can be fully achieved under some acceptable constraints.