We present the Operator design pattern which can be used for the design of both sequential and data parallel applications. To reach this goal, we show how the participants of this pattern can be implemented either for a sequential or a parallel execution. Besides, reusing the sequential design for a parallel application decreases the cost of parallelization by allowing the maintenance of a unique application for the two execution environments. The proposed approach for parallel programming does not require any dedicated compiler or code pre-processing. Nothing but object oriented features, such as inheritance and polymorphism, is used to provide the distributed behaviour of the parallel participants of the pattern. The Operator pattern can help to solve many design issues in relation with the development of reusable software components for data collection processing. Moreover, we are confident that many programmers who want to migrate their applications towards parallelism can find it helpful.