ATC Professional white paper



  1. Usually well-defined scope, from:
    1. drawings
    2. specifications
    3. contracts
    4. permits, memos, etc.

  2. Scope is static. Few changes occur during execution.

  3. Can be planned and scheduled well in advance of the project.

  4. Projects are organized around cost codes / commodities.

  5. Generally do not require safety permits to perform work.

  6. Manpower staffing requirements usually do not change during project execution.

  7. Project schedules can be updated either weekly or monthly.

  8. Projects measure time in days, weeks and months.

  9. Project scope is usually all mandatory.

  10. Project schedules are uncompressed. Schedule acceleration can be used to correct slippages in the critical path.



  1. Usually loosely defined scope, from:
    1. past turnaround experience
    2. inspection reports
    3. operations requests
    4. historical estimates

  2. Scope is dynamic. Many changes occur as inspections are made.

  3. Planning and scheduling cannot be finalized until the scope is approved, generally near the shutdown date.

  4. Turnarounds are work order based.

  5. Turnaround work requires extensive permitting every shift.

  6. Manpower staffing requirements change during execution due to scope fluctuations (from discovery work).

  7. Turnaround schedules must be updated every shift, daily.

  8. Turnarounds measure time in hours or shifts.

  9. Turnaround scope is flexible. Usually a large percentage of work can be postponed to a later window of opportunity if necessary.

  10. Turnaround schedules are compressed. There may be little or no opportunity to correct the critical path by accelerating the schedule.