Moreover, in practical product development process, resource constraints from machine equipment, staffs, and so on should be considered, but the traditional methods cannot Docetaxel solubility deal with this problem. Therefore, in this paper, we use DSM to identify and analyze design iteration. In current researches, only

valid iterations were considered, but some invalid especially harmful ones were not studied. However, due to the existing of these invalid iterations, the whole product design and development process may not be convergent. As a result, how to avoid these harmful iterations needs further study. In this paper, we use tearing approach combined with inner iteration technology to deal with task couplings, in which tearing approach is used to decompose a large coupling set into some small ones and the inner iteration technology to find

out iteration cost. The paper is organized as follows. In Section 2, we survey the previous literatures on disposal of coupled relationships. Section 3 presents the model for solving coupled task sets based on tearing approach and inner iteration technology. In Section 4, an efficient artificial bee colony algorithm (ABC) is used to search for a near-optimal solution of the model. In Section 5, the model is applied to an engineering design of a chemical processing system and some discussion on the obtained results is also given. Section 6 offers our concluding remarks and potential extensions of this research. 2. Related Works DSM is an efficient management tool for new product development. In the past decades, many researches have shown its efficiency. Currently, DSM has been widely used in decomposition and clustering of large-scale

projects [3, 4], identification of task couplings and minimization of project durations [5, 6], project scheduling [7–10], and so on. Because coupling of tasks is a key characteristic of product development, how to deal with couplings among tasks is a hot issue in present. Yan et al. [11, 12] focused upon the optimization of the concurrency between upstream product design task and downstream Entinostat process design tasks in the concurrent engineering product development pattern. First, a new model of concurrent product development process, that is, the design task group model, was built. In this model, the product and process design tasks were carried out concurrently with the whole design process divided into several stages, every two of which are separated by a design review task. The design review tasks might lead to design iterations at a certain rate of probability. Therefore, a probability theory-based method was proposed to compute the mean duration of the design task group and the mean workloads of all the design and review tasks, with design iterations taken into consideration.