Principles
Costing and controlling a project that lasts ten years.
Waterfall is designed for long-running projects: the offer is negotiated for months, the baseline moves only by contract, and the question “are we still where we said we would be?” must find an answer years after those who asked it have left. These seven principles follow from that.
Schedule and estimate
The schedule and the estimate are not two documents to keep in sync: a task carries its estimate lines, and moving the task moves what it costs.
Read the principle → 02Revisions
Every offer and every review is frozen as a complete revision, with the hourly rates and calendars that computed it.
Read the principle → 03Baseline and estimate to complete
Each line carries a budgeted amount, which only a contract amendment changes, and a re-estimated amount, which every review updates.
Read the principle → 04Risk provisions
A risk is costed like an estimate. Its provision weighs on the forecast but never enters the baseline budget.
Read the principle → 05Earned value
A completed task earns its budgeted amount. No percentage of progress is entered, so none is up for debate.
Read the principle → 06Portfolio
A portfolio index is a ratio of sums, never an average of indices.
Read the principle → 07MS Project, Excel and ERP
MS Project, Excel and the ERP stay in place. Exchanges are made by file, with a report before each import.
Read the principle →Why principles, and not a list of features
Most cost tracking tools can enter a budget, import expenditure and draw curves. What sets them apart are the rules that decide what a figure means: when is the budget allowed to move, what it means for a task to have “progressed”, where does the money set aside for risks go. These rules are what make a tool reliable or, without anyone noticing, optimistic.
Waterfall’s principles are those rules. Each one is backed by requirements of the public specification, which give their rationale and the criterion that will be used to verify the software.
Three roles, one set of shared reference data
Waterfall describes three typical roles. They are not fixed privileges: every action is subject to a permission, and an organisation can distribute those permissions differently.
- The project manager builds the offer and controls execution: schedule, estimate, risks, estimate to complete, import of actual costs, reading the indicators.
- The manager maintains the shared reference data (organisation, resource roles, calendars, cost types and categories, hourly rates, alert thresholds) and reads the portfolio views.
- The administrator manages accounts and permissions, monitors the platform and its backups, and consults the audit log.
What Waterfall is not
The scope is deliberately narrow. Waterfall manages neither sale prices, nor revenue, nor margin. It does not produce actual costs: it imports them from the ERP. It manages neither purchasing, nor orders, nor timesheets. It imposes no internal process. And it is not a work management tool like Jira or OpenProject: it schedules and costs by resource role, not by named person, and it does not assign tasks.
The terms used on these pages are defined in the glossary.
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Waterfall is built in public. Testers, project managers, cost controllers, developers: every piece of feedback counts, from a remark on the specification to testing a screen.