In short
Start with the five highest-stakes procedures (procurement, spending, revenue, recruitment, payment). For each: purpose, actors, steps in order, documents produced, control points and lead times. Have it validated by those who apply it, circulate it, then check application and update it every year.
1. Map the processes
List the organization’s processes and rank them by stakes: money committed, legal risks, volume. This ranking sets the order of writing.
2. Describe actual practice
Interview those who carry out the procedure and describe what really happens before improving it. A procedure written from an office, without the operators, will not be applied.
3. Build in controls
Separate incompatible tasks (commit, verify, pay), state who approves what and at which threshold, and plan back-ups. A flowchart per procedure makes it readable.
4. Keep the manual alive
Circulate, train, then check application by sampling. Every audit, complaint or regulatory change triggers a dated update.