A decision tree for recurring site calls: known answers, unknowns and actual authority
Foremen call the superintendent repeatedly about changing delivery slots. Some calls need only a confirmed booking; others involve unresolved access or a technical receiving condition. The team wants a simple decision tree that delegates the agreed coordination decisions without letting a chart turn missing information into permission to proceed.
Choose a bounded recurring call and draw how known information reaches the appropriate decision or escalation. Agree the questions, criteria and authority with the responsible roles before use. Unknown information needs an explicit route, rather than being treated as a favourable answer. In BC, WorkSafeBC provides a specific unsafe-work reporting and investigation process; a coordination tree cannot replace that process or remove its protections.
Build the unknown branch before posting the tree
- Bound the decision and delegated authority. State what the foreman may decide, under which current arrangements, and what remains with others. For delivery slots, separate confirming an available agreed booking from changing assessed access or receiving capacity. Avoid a broad 'work or stop' chart that implies a few planning questions authorize every operation.
- Use criteria from the actual arrangements. Identify the current information, contact, commitment or reviewed limit needed at each question. Have technical or safety criteria supplied and accepted through their appropriate process. A forecast, booked inspection or available pump is not universal proof that a pour or other task is ready. Keep those approvals outside an informal booking tree.
- Show no, unknown and changed-condition routes. Give each unresolved answer a receiver and useful response time. Make urgent hazards follow the actual immediate arrangements, without waiting for the superintendent's routine availability. Preserve the required refusal and investigation route where applicable. Unknown status should never default to yes merely because the chart needs a simple ending.
- Test, revise and control the current version. Walk through representative past and hypothetical cases with the intended users and responsible reviewers. Examine where assumptions or missing branches change the result. Agreement with previous decisions is not proof those decisions were right. Record approval, source changes and review ownership, then remove obsolete copies when the arrangement changes.
Common mistakes
- Drawing branches before defining actual authority.
- Using missing information as a favourable answer.
- Treating agreement with past calls as proof of correctness.
- Letting a planning chart replace a required safety process.
Checklist
An assessed recurring-call tree includes
- A defined decision and delegated boundary.
- Current criteria and their actual sources.
- No, unknown and changed-condition receivers.
- Immediate arrangements and protected safety routes.
- Case checks, current version and review ownership.
Check your understanding
Four of five past cases match the tree, but the fifth has unknown access. Should the tree be posted as validated?
