The purpose of this study is to develop an adaptive model of a very large scale data processing and storage environment. The target environment includes grid applications such as health-care and finance in which the data may be located primarily within the resources of a worldwide corporation. The approach is to use phase identification techniques that can detect over-utilized grid resources, and then to make dynamic decisions to reassign additional resources to that portion of the application processing. Two phase identification techniques are proposed, a variation technique and a real-time threshold-based technique. The techniques are validated with a simulation model and a case study using measured data from a production grid environment. The case study demonstrates that phase identification techniques can be used as the intelligent component of a reactive mechanism for a grid to adapt to changing environmental conditions by dynamic automatic reconfiguration. Results show that threshold based phase identifying techniques combined with dynamic resource allocation capabilities are effective in alleviating performance hot spots and improving response time in a large scale data grid