Project Schedule

A. Definition

Schedule is a time and resource control and management tool, identify activities for entire project with time scales and required resources. The Schedule is a plan for completion of a project, list of planned activities to be done within allowed time frame. A Type of Schedule in technique is a Bar Chart or Gantt Chart; PERT (Program Evaluation Review Technique), Network or CPM (Critical Path Method) and Detailed Reports (e.g. document issue schedule, material delivery schedule, etc.) Schedule. A Level of Schedules are a Project Master Schedule (Level 1), Project Summary Schedule (Level 2), Control Level Schedule (Level 3) and Detailed Network Schedule (Level 4), and Reports Schedule (Level 5). The Master or Project Summary Schedule is one of the contract document, and the Control Level Schedule is a project baseline document. A Scheduling is an evaluation of activities starting and finishing plan considering each activity's duration, predecessor activity, relationships, required resource availability, and target completion date of the project. Resources and cost usually are critical consideration. 

B. Type of Schedule

Bar Chart Schedule is a graphic presentation of work activities shown by a time scaled bar line.
Gantt Chart is one of the schedule control and management tool, shows bar chart with activities and time scale. Gantt Chart schedule invented in 1917 by the US engineer, Henry Gantt.
Program Evaluation Review Technique (PERT) is one of the schedule control and management tool for planning and evaluating progress of complex programs, shows graphical relations among activities, and time scale of each activities, and required total duration of the project. PERT was developed by US Navy in the 1950s.
Network Schedule (Scheduling) is a graphical display of logical order of activities and a method of scheduling work process where various related events are programmed into a sequential network on the basis of starting and finishing dates. The Network Scheduling shows the project critical path (sequential activities have zero float). Often called as a CPM (Critical Path Method) Schedule
Critical Path Method (CPM) is a most popular network schedule management and control tool, shows activities sequences (predecessor and successor) and relationships (finish to start, finish to finish, start to start, start to finish) of each activities, and the longest path resulting from complete works or tasks is called the critical path. The CPM is supporting tool for developing the shortest duration to complete the project, and the best way considering all resources mobilisations to complete the project. The CPM was developed in the late 1950s by Morgan R. Walker of DuPont and James E. Kelley, Jr. of Remington Rand. The most common tool for a CPM schedule is the Primavera software.

C. Level of Schedule

Project Master Schedule (or Level 1 Schedule or Management Level Schedule or Major Milestone Schedule or Report Schedule) is a simplest detailed project schedule, it highlights major project activities and milestones shows on an entire project calendar, and usually developed on the one page and used a bar chart or Gantt chart technique.
Project Summary Schedule (or Level 2 Schedule) is a high level integrated of engineering, procurement, construction and start-up activities for the entire project time frame, shows the project milestones, key deliverables divided by units and system facilities includes key critical activities and units or systems used for high level internal and external management reporting. The Project Summary Schedule is developed, usually, as a summarisation of the Level 3 Project Schedule (Project Control Schedule).
Control Level Schedule (Level 3 Schedule or Network Schedule) is an actual project schedule control and management tool for a work level. The Project Control Level Schedule is integrated detailed EPC activities for the entire project scope of work based on a Critical Path Method (CPM) used a network scheduling technology with detailed input all major milestones, major elements of design, engineering, procurement, construction, pre-commissioning, commissioning activities. The Project Control Level Schedule shows detail and individual work tasks and clearly defined works by discipline or responsibility. This is a first level of detailed schedule that a meaningful critical path management can be performed to monitor and manage the overall project work accurately, and usually basis of a look ahead or window schedules for the project schedule control and management.
Detailed Network Schedule (Level 4 Schedule or Execution Schedule or Construction Detailed Schedule) is a detailed and discipline-wide working level network critical path management (CPM) schedule displaying all detailed activities to be accomplished by the project workforce. The Detailed Network Schedule can be expanded of the Project Control Level (Level 3) Schedule. Sometime, the Detailed Network Schedule is developed by a construction subcontractor based on the project level 3 schedule.
Detailed Report Schedule (Level 5 Schedule) is a detailed report format schedule, covers detailed activities with work steps, normally used for project documentation, engineering deliverables and procurement items.

D. Other Definition

Front End Schedule is to provide a project overall schedule shown the starting and ending date and to use a status reporting, usually a bar chart schedule.
Look Ahead Schedule (or Window Schedule) is shown a present time period, previous and future time period, 3 weeks for a weekly or 3 months for a monthly look ahead schedule.
The Primavera is a network schedule control software, was launched in 1983 by Primavera Systems Inc. and was acquired by Oracle Corporation in 2008. Primavera software includes project management, collaboration and control capabilities and integrates with other enterprise software such as Oracle or SAP’s ERP systems. Primavera P6 Enterprise Project Portfolio Management is the most powerful, robust, and easy-to-use solution for globally prioritizing, planning, managing, and executing projects, programs, and portfolios in asset-intensive industries (Oracle).