When you are about to implement Nirmalya Enterprise Resource Planning (NERP) system, one crucial step to ensure success is performing User Acceptance Testing (UAT). This involves simulating a real-world scenario for end-users and observing the software responses to evaluate if they meet user needs and expectations. Here, we provide a checklist to guide you through a thorough UAT process.

User Acceptance Testing (UAT) aims to confirm that an ERP system functions as intended, meeting both business requirements and user expectations. It's a crucial phase in NERP implementation where end users try out the system before it goes live.

1. Clearly outlining the project's scope involves identifying the user's requirements, intended goals, success parameters, and timelines. Decide on the business processes needing testing and their expected outcomes, ensuring to adhere strictly to this scope to avoid project creep.
2. Develop an overall test plan consisting of broad real-world scenarios and specific test cases based on the defined scope. Make the test cases clear and easy to follow, covering all relevant processes as outlined in the scope.
3. The data used for testing should simulate actual use cases and real-world scenarios. Ensure this by equipping your testing environment with realistic data that closely mirrors daily operations without infringing privacy.
4. Choose testers who are likely to use the software daily, such as business users directly handling ERP modules, subject-matter experts, and business analysts. They should possess critical thinking skills and understand the software's purpose thoroughly.
5. Deciding the sequence of tests is crucial, especially when working on a large test suite with limited time and resources. Identify critical business processes first before specialized use cases.
6. End users should receive ample training and support as it’s typically the first time users encounter the new software. If users are not comfortable with the system, detected errors could be mistaken for bugs, overlooking significant issues.
7. Thoroughly record any defects encountered during testing, including screenshots, videos, and text notes. Documenting these details will help testers recall specific issues and assist developers in understanding how these issues arose.
8. Maintaining open communication between end users and developers through feedback loops can facilitate continuous improvement and evaluation. Regular check-ins and meetings help foster collaboration.
9. Perform regression testing each time issues are addressed, regardless of their scale. Without such, you run the risk of repercussions in parts of the system previously working correctly, which could be detrimental.
10. Implementing UAT systematically is essential, even though it might seem daunting. Underestimating UAT's time demand can lead to skipped test cases, eventually resulting in undetected defects.

In summary, careful planning, coordination, and execution can indubitably run an effective UAT in NERP implementation.