Flash-memory based Solid State Drives (SSDs) embrace higher performance and lower power consumption compared to traditional storage devices (HDDs). These benefits are needed in HPC systems, especially with the growing demand of supporting Big Data applications. In this paper, we study placement and deployment strategies of SSDs in HPC systems to maximize the performance improvement, given a practical fixed hardware budget constraint. We propose a pattern-model approach to guide SSD deployment for HPC systems through two steps; characterizing workload and mapping deployment strategy. The first step is responsible for characterizing the access patterns of the workload and the second step contributes the actual deployment recommendation for Parallel File System (PFS) configuration combining with an analytical model. We have carried out initial experimental tests and the results confirmed that the proposed approach can guide placement of SSDs in HPC systems for accelerating data accesses. Our research will be helpful in guiding designs and developments for Big Data applications in current and projected HPC systems including exascale systems.