Meeting the continuously evolving design requirements for air and land based gas turbine engines requires improvement in the design methodology to improve current combustor designs and also evaluate novel concepts. Gas turbine combustor performance parameters include pressure drop, combustion efficiency, emissions etc. Several of these parameters are conflicting objectives and hence a comprehensive design methodology is required to optimize combustor performance. Combustor design methodologies use empirical correlations, flow network solvers, CFD solvers and a combination of these. In the current work, we propose a design methodology for preliminary combustor design that tries to incorporate all of these objectives together and explores the design space for robust optimization. Current progress includes validation studies on a can type combustor and a parametric design study with three geometric design variables and five objectives on the can type combustor.