Final answer:
The success of a new point-of-sale system is most effectively measured by user satisfaction and adoption, as these factors directly reflect the system's performance in everyday use.
Step-by-step explanation:
When assessing the success of a new point-of-sale system implementation, user satisfaction and adoption will be most indicative of the project's success. Although factors like the number of employees involved, the budget allocated for the project, and office layout design play a role, they are not as directly tied to the effectiveness of the system. User satisfaction ensures that the system meets the needs of those who use it daily, which is crucial for a point-of-sale system that is integral to operational efficiency and customer service. High user adoption rates similarly suggest that the system is well-designed and aligns with workflow, leading to improved productivity and, potentially, positive financial outcomes. It's important to involve all stakeholders to get buy-in and to consider the practical and detailed aspects of design as these will heavily influence the implementation phase.