To maintain the length of the project ID, you can use the project coding mask. The project ID is a parameter that uniquely identifies a project in SAP systems. The project ID consists of various characters that represent different levels of a project structure, such as project definition, WBS element, network, and so on. The project coding mask is a parameter that defines how a project ID is structured and formatted. The project coding mask consists of various symbols that represent different segments of a project ID, such as special characters, digits, letters, and so on. To maintain the length of the project ID, you can use the project coding mask by specifying how many characters are allowed for each segment of a project ID. You can create and maintain project coding masks in Customizing forProject System under Structures Operative Structures Work Breakdown Structures Define Coding Mask . Reference:https://help.sap.com/doc/0f069b2e08b748f1b480d4c8b46c3c49/100/en-US/6a7a9f0a6e421014e10000000a174cb4.html