Abstract Design patterns are micro architectures, high-level building blocks which describe the solutions to speci c problems in software design. These solutions have generally been developed and evolved over time. It has been claimed that design patterns are capable of: (i) simplifying the design, implementation, and maintenance of complex systems, and (ii) improving the quality of software systems. However, in all the prior works reported in the literature, the claimed evidence has been of a qualitative nature. This research deals with collecting metrics which can be used to measure the impact of design-pattern-based systems on maintainability of parallel applications. In addition, we also measure the software complexity of these applications based on the de nition of complexity by other researchers. To the best of our knowledge, this is the rst work to evaluate the in uence of designpattern-based systems in a quantitative manner.