## 3 The Early Phase Project Scope Estimation Methodology
### Requirements Workshop  
The requirements workshop is a collaborative session conducted to gather, refine, and clarify requirements for a project or product development. It is a technique commonly used in Agile and Lean methodologies to streamline the requirements collection process. The workshop involves different stakeholders, such as business sponsors, domain experts, actual users, product owners, developers, designers, testers, business analysts, architects, etc. This diversity ensures that various perspectives are considered. Workshops are usually time-boxed, meaning that they have a limited duration, often ranging from a few hours to a day or two. This time constraint helps maintain focus and prevents the workshop from becoming overly lengthy and unproductive. The goal of the requirements workshop is to create a common understanding among stakeholders and team members about the project goals and scope. Participants engage in various interactive activities to discuss, document, and prioritize requirements. These activities might include brainstorming, user story mapping, process flowcharting, and collaborative discussions. Workshops often utilize visual aids such as whiteboards, sticky notes, and diagrams to help participants better understand and visualize requirements. Participants who are familiar with modeling languages can prepare various diagrams, using popular notations, such as UML or SysML. Visual representations can make complex ideas easier to understand and communicate. The variety of visual model representations ensures that each workshop participant can properly get involved and can contribute to preparing an initial list of requirements. The most used visualizations are the Story Map, UML Use case model, UML Activity model, and SysML Requirements model. If the participants have more technical experience, they may use the UML Class model. If the team does not use visualizations but only compiles lists of requirements, e.g., in Excel spreadsheets or Gannt Chart based tools, then the risk of wasting more time, missing process steps, users, risks, etc., increases. The assumption that modeling is time-consuming is incorrect if the level of detail of the models is properly defined. The recommendations for achieving the optimal level of detail for the models prepared during the requirements workshop are presented in Table 1.  
Figure 1: Overview of the early phase scope estimation methodology.  
The main difference between the preparation of models in Agile and Waterfall projects is their detail. This is because the purpose of models in Agile projects is to facilitate a common understanding of the project and requirements guidelines, as the details will change over time. Waterfall projects require precision and detailed information already in the analysis phase, and this phase often lasts from one to several months. In Agile projects, the time to agree on the scope of the project and the main requirements for the first phase of the minimum viable product (MVP) is very limited.  
In the proposed methodology, there is no limit to how many and what models team members can create during the requirements workshop. The goal is not to limit the participants, but to give them the opportunity to effectively synchronize the available information, fill in the gaps, and move to the scope assessment stage. This process is very fast, and the goal is not to obtain all the details, but to ensure wide coverage from various viewpoints and general mutual agreement. In Agile projects, the details are worked out as the project progresses.