A proposal is technically complete when it explains not only the product and headline scope, but also integrations, data migration, environments, security, non-functional needs, ownership, testing, cutover, support, assumptions, exclusions and acceptance. The key test is whether another competent team could understand what will actually be delivered and operated without relying on unstated knowledge.
Look for hidden work
Migration cleaning, interface development, master data, identity setup, reporting, testing, training, cutover and support transition are common areas that appear only as assumptions.
Trace to the business
Each major requirement should connect to a business need or operating constraint. A technically impressive proposal can still solve the wrong problem.
Before signing
Turn gaps into explicit questions, contractual scope, acceptance conditions or priced options rather than leaving them to be discovered during delivery.
How soapplied approaches the question
I would not start by assuming the stated problem is the whole problem. The first step is to understand the people, purpose, constraints and interactions around it, then test what intervention would improve the system rather than merely optimise one component.