Coalescence consists of four steps: approach of droplets pair, drainage of the matrix between the droplets, matrix breakup at critical interdroplet distance, and shape relaxation of a new droplet. This communications is based on research of the second coalescence step in systems, where the driving force is a gradient of flow velocities of matrix, while the droplet approach is slowed down by drainage of the matrix film between droplets. We have recently extended the Jeelani and Hartland equation, combining it with the fully mobile interface model, to a model describing the flow-induced coalescence in the whole viscosity range. We have used the arbitrarily mobile interface model (AMI) name to refer to it. The new AMI method is semi empirical and its dimensionless parameters can be determined more precisely by broader comparison with experiment.