## 2 Literature Review
### Success Measurements  
To measure success, specific tolerances need to be defined. For each assessment area, success and failure criteria should be defined to gain a better understanding, avoid wrong expectations, and foster a clear and understandable communication. This can be achieved, for example, by using control charts. To achieve this, these criteria and tolerances must be collected from all (key) stakeholders from the beginning of the project to analyze if the requirements are viable, desirable, and achievable [40]. All stated and agreed target values and limits need to be SMART (Specific, Measurable, Achievable, Realistic, and Timebound). After that, these requirements and expectations need to be balanced and managed [75,76], since different levels or areas could conflict with each other or be contrary. Then, problem solving must be applied to balance these or to identify higher priorities and to find, in the best case, acceptable solutions for all stakeholders. Several factors can influence these processes, which are highly dependent on the situation. Furthermore, success criteria can be defined with a weighting factor or as primary or secondary [48]. The different views on the defined success criteria from (key) stakeholders should be collected and deviations should be discussed. In case parties cannot understand each other or disagree with some points which would create conflicts, a third (neutral) party can be involved, which can moderate to reach a consensus as well as conduct an assessment from an independent standpoint, or to accept knowingly an unsatisfied stakeholder with expectable consequences. All of this must be contained in the project management methodology as a formal step to control and assure that the right criteria will be considered. \begin{table}
\begin{tabular}{c c} \hline No. & **Operations Success Criteria** & **Reference** \\ \hline
33 & Operation stays within the defined budget & [41,62] \\
34 & Operation delivers the desired outcomes (as the fundamental business objective (the fulfillment of the project objective) and that have been developed in accordance with the core competencies of the organization) & [64] \\
35 & Operation delivers the desired impacts (expected benefits evaluated for the project portfolio as a whole) & [64] \\
36 & Operation delivers the desired value (the performance measures in the conduct of operations) & [71] \\
37 & Actual use by the customer & [51,74] \\
38 & Workplace security & [69] \\
39 & Downtime (e.g., maintenance, repair) & [69] \\ \hline \end{tabular}
\end{table} 
Table 4: Operations Success Criteria. \begin{table}
\begin{tabular}{c c c} \hline No. & **Deliverable Success Criteria** & **Reference** \\ \hline
26 & Completed within defined and agreed budget & [72] \\
27 & Return on Investment of the project & [64] \\
28 & Knowledge generation regarding project management (e.g., tools, techniques, approaches, processes) & [64] \\
29 & Publications regarding project management (e.g., tools, techniques, approaches, processes) & [49] \\
30 & Customer satisfaction regarding the management of the specific project & [64] \\
31 & Project management processes were conducted within the organization’s quality standard & [64] \\
32 & Resources for project management activities were mobilized and used as planned & [64] \\ \hline \end{tabular}
\end{table} 
Table 3: Deliverable Success Criteria. Moreover, as described before, success is not a one-time definition. It evolves and develops over time. Consequently, the definition must be continually revised if needed. Along with that, it needs to be defined when and how the success can be measured. Another point which influences the assessment of success or failure is the person who conducts the assessment [24; 62]. As stated before, general success criteria need to be developed for an organization to be able to compare projects. Nonetheless, distinct criteria need to be defined to do justice to the uniqueness of each project [46].