Process Control & Schedule Hierarchy

A Schedule Hierarchy defines the schedule control system and several interrelated levels of schedules at various levels. Schedule hierarchy provides a framework for project schedule development.

Primarily, there are following 4 level of schedules being applied on medium to large size projects to identify the scope and division and as well as contractual/project milestones.

Level I: Milestone Summary Schedule

Depicts overall time frame of project, covers total project scope and highlights contractual and Project milestones. This schedule is used by Management to highlight major and significant events as well as to communicate overall scope and status of project. This level schedule can also be used for decision making.

Level II: Summary Schedule

Level II Schedule is summarized by facility, discipline and areas for Engineering, highlighting long lead items, critical items for Procurement, and summarized by work package for Construction. Level II schedule establish requirements at the facility level, phase or work phase. It depicts the relationship between facilities/phases and establish facility criticality.

Level III: Detailed Engineering, Procurement and Construction Schedule

Integrated EPC Schedule where Engineering is sorted by discipline, grouped by systems/area depicting system requirement. Procurement identifies demand by facility/area or systems and as well identify the major equipment delivery. Construction/startup is grouped by system/area depicting interrelationships and timeframes. Level III Schedules establish the basis for staff requirements Task deliverables, material and subcontract requirements and bull release and installation rates. Level III schedule establish construction equipment requirements and integrates facility/area breakdown into system turnover packages. Level III schedules are maintained at regular basis and used for What-if analysis.

Level IV: Identification of detailed work plan, log list

 Level IV schedule is broken down at work activity level i.e., drawings, specs, data sheets etc. It depicts construction by work package/area/facility/craft/crew and establish construction sequence. Level IV schedule provides basis for detail construction work planning and rolling schedules and its a working document that is continually updated and revised to reflect project needs and circumstances.

Schedule Baseline Process

Schedule must be baselined to map it to current schedule to avoid slipages and to get early warnings. This also assists in developing planned S Curves and histograms to keep the current schedule on track.