en کنترل پروژه Project Control پژوهشي Research <p>The concept of &quot;complexity&quot; is familiar to most of project&#39;s managers, but it is not comprehended in the same way. although the complexity highlights negative points, but it may bring positive advantages which support the project. Researches conducted on this field show that the understanding of &quot;complexity&quot; between the researchers is different and it is mainly depends on their points of view. In fact, many identified aspects of the complexity in the literature are related to the aims of the research. In this paper, an attempt was made to describe the positive / negative features of the complexity of project using three approaches research literature (manufacturing and project complexity), interviews (deep interview with 20 experts) and questionnaire. The research was conducted on the Complex product and system (CoPS) projects. in addition, WH question technique was used. In conclusion, a 5p model (Purpose, Product, Process, People, Peripheral) has been introduced as the outcome of the study.</p> <p><img alt="AWT IMAGE" src="./files/site1/images/6.png" style="width: 250px; height: 250px;" ></p> Complexity , Project Complexity, Manufacturing complexity Factors of complexity, Modeling Complexity, conceptual model 311 332 http://ijiepr.iust.ac.ir/browse.php?a_code=A-10-13-1&slc_lang=en&sid=1 amir mohammad Sanati gmsanati@iust.ac.ir 180031947532846003517 180031947532846003517 No Department of Industrial Engineering, Iran University of Science & Technology siamak noori snoori@iust.ac.ir 180031947532846003518 180031947532846003518 Yes Department of Industrial Engineering, Iran University of Science & Technology