PurposeThis study aims to determine the relationship between sectional geometric parameters of a slotted solid rocket propellant on structural integrity and internal ballistic performance of a rocket motor by using response surface method.Design/methodology/approachZero-dimensional (0D) ballistic solver is developed and validated to determine the effects of sectional geometric parameters on internal ballistic performance of a rocket motor. Additionally, effects of these parameters on structural strength of the system are examined by performing linear viscoelastic finite element analysis under plane strain assumption. Results of the 0D internal ballistic analyses are used as an input to the structural analysis.FindingsDifferent response surfaces are constructed to represent the characteristic variation of solid propellant’s structural strength and internal ballistic performance with respect to design variables.Originality/valueCoupled analysis methodology in terms of structural strength and internal ballistic performance presented in this work facilitates many designers who are working on solid rocket motor development. This study represents graphical results summarizing effects of sectional parameters of a slotted grain on both internal ballistic performance and structural strength results. Additionally, graphical results summarizing the effects of sectional parameters on structural strength and internal ballistic performance provide useful information for researchers that lessens design period. Finally, validations presented in this work can also be used as a benchmark reference for different studies.