To ensure that valid data is used in a case, you need to make sure that the data fits the business logic and the data is the correct field type. The data fits the business logic means that the data conforms to the rules and constraints that define the business problem and solution. For example, you can use validations, calculations, and dependencies to ensure that the data fits the business logic. The data is the correct field type means that the data matches the expected format and structure of the field that stores or displays it. For example, you can use different types of fields and controls to ensure that the data is the correct field type. References: https://community.pega.com/knowledgebase/articles/user-interface/86/ensuring-valid-data-used-case

The three options that are application layers in the Situational Layer Cake architecture are implementation, division, and organization. The implementation layer contains the case types and data types that are specific to a single implementation of an application. The division layer contains the rules and data that are shared by multiple implementations within a division or a business unit. The organization layer contains the rules and data that are common across the entire organization or enterprise. References: https://community.pega.com/knowledgebase/articles/application-development/86/application-layers