Fork/join stations are commonly used to model the synchronization constraints in queuing models of computer networks, fabrication/assembly systems and material control strategies for manufacturing systems. In many such applications the fork/join station is fed by two or more inputs from finite populations. This paper presents an exact analysis for the case when the input processes are renewal and the inter-arrival times have two-phase Coxian distributions, allowing us to model a wide range of variability in the input processes. The underlying queue length and departure processes are analyzed to determine performance measures such as throughput, mean queue lengths and distribution of inter-departure times from the fork/join station. The results show that, for certain parameter settings, variability in the arrival processes have a significant impact on the performance of the fork/join station. The model is also used to study the sensitivity of performance measures such as throughput, mean queue lengths, and variability of interdeparture times for a wide class of input processes and customer populations.