Stimulated reservoir volume (SRV) seldom provides an actual producible reservoir volume in gas shale reservoirs. It is determined by analysing microseismic events induced by a network of hydraulic fracture and reopened natural fractures. However, the occurrence of noncontributory microseismic events leads to an overestimation while the presence of natural fractures leads to an underestimation of producible reservoir volume. A relatively new concept used to quantify actual producible reservoir volume is the effective stimulated reservoir volume (ESRV). ESRV is essential in estimating ultimate recovery, propped volume, optimal fracture length, and spacing. This paper presents an outlook on the evolution and development of various models used to evaluate ESRV. The respective advantages and limitations of the various methods are discussed. It is observed that integrated modelling approaches, such as by using rate transient analysis and discrete fracture network modelling, are more efficient to characterise and describe the ESRV. Such an integrated approach should consider the stress/pressure dynamics, reservoir permeability, flow and fracture geometry which are vital for accurate ESRV characterisation. © 2021 Elsevier B.V.