Count workflows before screens
A simple-looking screen may contain complex permissions, calculations or integrations. Estimate the behavior behind it: who can change a record, which validations apply and what happens if a connected system fails.
Describe the first release through a small set of complete user journeys. For each journey, list the required data, integrations, roles and acceptance checks. This provides a more useful estimating unit than an isolated feature name.
Separate known work from uncertainty
Break the estimate into discovery, design, implementation, testing, deployment and handover. Use ranges where requirements or technical constraints remain unresolved. Record the assumption behind each range and how it can be tested.
A short technical experiment may reduce uncertainty around an unfamiliar integration. User research can establish whether a requested feature is needed at all. Treat these as deliberate investments in a more reliable scope.
Compare complete proposals
Check whether estimates include content migration, accessibility, operational tools, security review and post-launch stabilization. A lower total can reflect a smaller scope rather than greater efficiency.
Separate build costs from hosting, licenses, support and future changes. Agree how scope changes are approved and what evidence demonstrates completion. A useful estimate helps you make decisions during delivery, not just authorize the start.