Introduction Project management attracts the attention of academics and project professionals. Understanding of project complexity and how it might be managed is very important for project’s success. Before any measure of success can be obtained, it is essential to first identify what the project is and what the limitations are? In this direction, the main purpose of this paper is to determine what is meant by project, to identify the factors which make a project as opposed to routine work and project success criteria. Firstly, the essay will identify concept of project management requirement. Secondly, the essay will focus on project definition and differences from operation. After that, the essay will examined an iron triangle role in project success. Then, how and when the project success is measured questions will be answered. Finally, the iron triangle’s weaknesses will be evaluated and an extended triangle shape will developed instead of traditional iron triangle. At the end, the essay will be completed with summary and personal recommendations.MethodAn extensive review of the literature on project management and its impact on project’s success was undertaken. In total, more than 80 papers and books were reviewed with 15 of those being cited in this paper. The research has comprised of both qualitative and quantitative data.Key words: project, iron triangle, project management successAnalysis and Synthesis of the Task  After 1950’s, time and cost concepts were more important than before. Projects could not manage themselves and project management was defined a job. Project management was a guiding system to reach from the draft to the final stage. (Lock, 2018)Project is a chain of organized activities in order to reach the results. PMBOK defines a project as “A project is a temporary endeavour undertaken to create a unique product, service, or result. The temporary nature of projects indicates that a project has a definite beginning and end” (Project Management Institute, 2013, p. 1). For example, building a hospital is a project. However, operations at hospital after opening is not project because it is not one-off. Projects can be classified into four categories namely engineering/construction, manufacturing, management and science research (Lock, 2018).Albert Lester defines difference between routine work and project as “The answer is that project management is essentially management of change, while running a functional or ongoing business is managing a continuum or ‘business-as-usual” (Lester, 2017, p. 1)  According to Lientz (2013, p.3), “As such, projects are differentiated from regular operational work that is repetitive and well defined and that produces services and products”. Timeframe that is transient is the one of the major differences between project and “business as usual”. Business as usual is repetitive and on-going operations while a project is temporary. Project has a definitive end point. The project’s task should be unique and have never been done before. Operations do not bear the characteristics of the project. Operations do not produce an original (new) product or have a start and end point. “While projects require project management, operations require business process management or operations management” (PMBOK® Guide, 2008, p. 12). However, the project process or outputs may also affect operations.As is understood, every project is unique. For this reason, projects should be clearly defined before the beginning.Table 1: Key questions to complete project definition (Newton, 2016)PROJECT DEFINITIONPROJECT NAME:Why do you want to do this project?What will you have at the end that you don’t have now?Will you (should you) deliver anything else?Is anything explicitly excluded from project?Are there any gaps or overlaps with other projects-or changes to the boundaries of your project?What assumptions (if any) are you making?Are there any significant problems you are aware of that you must overcome?Has your costumer, or the situation, set any conditions on the way you do this project?Completed onCompleted byAgreed byThe “iron triangle” which includes cost, time and quality is a constraint for project management. This metaphor is a traditional way to measure the project success that is based on project objectives identified specifically and uniquely for each project. Delivering the project’s product in scope, time, cost, and quality is not only criteria for success. There is another deep perspective in modern project. The third dimension of iron triangle which is defined soft triangle also affects project success (Caccamese & Bragantini, 2012).  There are also metrics in addition to the iron triangle to measure success which are project risks, safety, health, environmental and security requirement (Khan, 2016). These two articles demonstrate that iron triangle is an insufficient method to measure project success. According to the Cambridge dictionary definition, the meaning of success is “the achieving of the results wanted or hoped for” (Anon., 2018). Meeting the clients’ requirements and expectations is the main criteria to achieve the success.The narrow perspective is a disadvantage of iron triangle which focuses on just time, cost, quality. The iron triangle is just a framework to assess management success. If a stakeholder is satisfied with project’s products even duration or cost increase, the project could be defined as successful. Hence, project success depends on stakeholder’s expectation. It could be the cost of the project, delivering the project on time or just final the product.  For instance, the Sydney Opera House was built in 15 years and the budget of the project exceeded the limit. This project was classified as successful because the engineering, architectural and society results and benefits are visible (Anon., 2017). So, in addition to the triple constraint model, stakeholder’s satisfaction is another important factor to determine the project success.Other weakness of the iron triangle could be concerning quality and future value. There is no certain definition for quality. The quality is changeable for each specific project. Moreover, the iron triangle is not a frame to evaluate how the project will add value to the client and to society in the short and long term (Madsen, 2013). It is clear that the aim of quality is to complete the project in accordance with the criteria requested by the customer and in quality. Unfortunately, this area remains many times behind time and cost. Quality is evaluated at the stage of submission to the customer. If the project is not in line with the conditions requested by the customer, it causes additional time and cost.Further criterion to measure project success is commercial success which provides new business opportunities. So, success of a project is affected by not only conventional iron triangle but also corporations and client side (Pinto, 2016, pp. 36-39).Extended iron triangle                             Time                                         Added Value Stakeholder satisfaction Budget                       QualitySource: developed for this study  Conclusion“Project success isn’t all black and white, there are grey areas that are a little more difficult to measure but are definitely worth taking the time to evaluate” (Eskander, 2018).Project Management is needed to ensure a project goes from start to finish with safe monitoring of the process.The traditional way of measuring project management success is often called the time–quality–cost triangle. Time, quality, and cost are the sides of the triangle. The triangle is not equilateral. The form of the triangle is flexible according to need and target. The triangle measures project management success not project success. Project success is relevant to stakeholder’s satisfaction. In addition, the project’s success is also affected by project value which include social environmental and monetary influence. The success of the project can be measured at the end of the project when stakeholders reach the intended project result.I think that project management is really important to measure project performance and the iron triangle is a necessity for sustainable project management. But, measuring the project success is not just linked with time, budget and quality. A project manager should pay attention to other metrics for each project. In my opinion, the result of meeting the stakeholder’s needs is the most important success criterion. For the success of the project, firstly, organizations have to define a project definition clearly. After that, they have to focus on stakeholder satisfaction within the scope of the iron triangle.BibliographyAnon., 2017. 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