The delay sensitive industrial control applications like Industrial process control, Environmental control, Gas leakage monitoring, etc. in this a reliable communication between sensor and base station are highly essential. Wireless Sensor Networks (WSN) becomes an immensely popular technology in such application as it offers low latency and high energy-efficiency in message transmission. Life span of the network can be extended by using appropriate energy efficient routing protocol. The three standard routing protocols, namely Ad-hoc On-Demand Distance Vector, Destination Sequence Distance Vector and Ad-hoc On-demand Multipath Distance Vector have been analyzed. In this work we have proposed multi-sink model to compare with conventional single sink model. We have designed probabilistic model to compare transmission delay in these two models. They are also compared with IEEE802.11 and IEEE802.15.4 MAC protocol. The proposed WSN model is analyzed by estimating end-to-end delay, energy consumption and packet drop ratio of both models. NS-2 simulator is used for result analysis in different traffic conditions. The Quality of Service can be improved by minimizing delay in packet delivery of the network. It has been observed that overall delay can be minimized significantly in proposed model.