Your Salesforce org is the master storage of all your business data. Depending on the areas that technician is working on, he would need access only to a sub-set of business data. Typically, he would need access to the work orders he is assigned to, related location, account, product, component, debrief information, and so on. Additionally, he would need access to various parts information, installed product repair history, Knowledge Base articles, and similar information.

Apart from the business data described above, technician needs to have access to key ServiceMax objects, Apex classes, and VisualForce pages, for successful operations. You can associate the standard ServiceMax Permission Set to the technician's Salesforce user record for this purpose. Refer to Data Model - Key Details and sections for more details.

The configurations in Salesforce determine which business data is accessible to the technician. ServiceMax configurations determine which sub-set of accessible data is downloaded to the mobile app.