As a general framework, UNITY does not offer any specific facility for the design of distributed systems. For such systems, distribution aspects must be represented at a low level, resulting into intricated models and proofs. To proore abstract view of distributed systems, we propose two extensions to UNITY. The first one is an observation relation which is integrated in UNITY seto provide an abstract communication mechanism. The second one is a mapping operator which accounts for the true parallelism of distributed systems. The paper illustrates, through different examples, how these extensions can be used to help the design of distributed systems in UNITY.