Soft pneumatic actuator (SPA) based devices often use heuristic approaches for designing the power and control system, which are not necessarily optimized for the application. Especially in portable applications, due to constraints on the overall size and weight, appropriate sizing, selection and design of pneumatic systems can greatly affect mobility and usability. As actuator output depends on flow and pressure dynamics, an in-depth study of the pneumatic circuit (set of interconnected components forming flow pathway) can give a deeper insight into this problem. While commercially available software packages can be used, the large number of parameters involved makes it difficult to clearly identify the individual contribution and combined effect of the components of the pneumatic circuit on actuator output. This work presents a simplified analytical approach for pneumatic circuit design for meeting desired actuator performance. A generalized model is proposed, and normalized with actuator size and flow conductance to get a reduced model. A parametric study of this normalized model is then carried out to quantify the effect of different aspects of the pneumatic circuit design on actuator performance, in terms of rise time and fall time. Using the results from this study, it is possible to design, inspect and optimize pneumatic systems to meet desired performance requirements. It can also be used for maximizing the output of a given system, or minimizing the weight in portable applications, thus enhancing mobility.