## 5 Evaluation
### Multi-Case Evaluation of DSML4 PT  
#### 5.2.1 Preparation  
As discussed in Section 5.1, research questions, use cases and the team of the evaluators are prepared in this phase. The conducted evaluation aims to answer the following research questions (RQs):  
_RQ1: To what extent does the use of DSML4 PT allow the automatic generation of the software components of an IoT-based public transportation system?_  
_RQ2: Does using DSML4 PT reduce system development time?_  
_RQ3: What are the pros and cons of using DSML4 PT from the perspective of the system developers?_  
To find the answers to the above RQs, our evaluation has two parts: (1) quantitative analysis including production performance and development time assessments, and (2) qualitative assessment from the user perspective. In this study, ten software developers, who are currently working or previously worked in the domain of public transportation, voluntarily participated as the evaluators. All evaluators had at least a B.Sc. degree in computer engineering or electrical engineering. Five of these ten evaluators had a M.Sc. degree in computer engineering, and two of these five evaluators were also pursuing Ph.D. degrees in information technologies at the time that this study was conducted. All of the evaluators were experts in developing public transportation IoT systems based on embedded software and IoT components, with varying experience from 3 to 16 years in the IT companies producing intelligent transportation system solutions for automated fare collection, vehicle tracking, real-time passenger information, etc. Specifically, the evaluators had an average of 4.5 years of experience in the design and implementation of IoT-based public transportation systems. Although they were mostly familiar with the UML and software modeling, five of them had previously used DSMLs and/or MDE techniques before this study. Development of the following eight different public transportation applications with varying complexities were taken into consideration as the use cases:  
1. Validator: Validators are one of the main IoT devices used in the public transportation systems. A validator is essentially a system for collecting fees from customers. Payment transactions can be made using media such as RF card, smart phone, or QR code. The system generally consists of a validator device software and a server software in the cloud used for one fee collection. Mobile phone applications can also be integrated into the system. 2. Advertising Management System: This is an IoT system where advertisement broadcasts are made in public transportation vehicles. It consists of an ad management software and cloud software. The ad management software is used by an admin to manage all system activities, while the cloud software holds interactions and ads in the system. 3. Air Pollution: This IoT system is used to monitor air pollution outside of public transportation vehicles. It consists of software that reads data from sensors and server software on the cloud, which handles all the information and statistics. 4. Passenger Count: This IoT system tracks the number of people in public transportation vehicles. It consists of sensors for passenger counting and software that reads data from the Global Positioning System (GPS) module, and a server software on the cloud. The server software manages location and passenger count information depending on the stops. 5. Passenger Information: These IoT systems provide updates on new stops and announcements for public transportation passengers. They consist of software that uses LED panels and LCD monitors, as well as cloud software that holds the required information and manages the interactions. 6. Temperature Sense: This application is used to send internal or external temperatures measured in public transportation vehicles to a cloud system. The cloud system stores the information and prepares statistical data representations. 7. Vehicle Management: This IoT system provides management for public transportation vehicles.