Delay in ATP-dependent calcium inflow may affect insulin secretion from pancreatic beta-cell

•A four dimensional delay model is considered to study insulin-glucose dynamics in the beta-cell.•Model was analyzed to obtain stability and bifurcation conditions.•Sensitive parameters of the model were determined using global sensitivity analysis.•Parameter recalibration exercise was used to identify possible restoration strategies.•Delay is found to be critical in maintaining insulin homeostasis.