The concept of scheduling to achieve success is not a new one. Sun Tzu wrote in The Art of War about scheduling from a military prospective in 6th century BC. His five fundamental principles for planning—the way, seasons, terrain, leadership, and management—have been followed throughout history by military planners for the successful achievement of their objectives. Not coincidentally, they are very similar to what is used in planning a complex construction project. The pyramids and the transcontinental railroad could not have been completed without some form of schedule that established the priority and order in which items of work were to be completed. While military leaders, railroad tycoons, and old time project managers must have had an appreciation and understanding of scheduling, there was little formal process until the 20th century.
In construction, critical path method (CPM) project scheduling has evolved from the original CPM created on the UNIVAC computer in 1956 with fewer than 300 activities, and requiring 300 hours of computer time to update, to today’s construction projects that often have more than 10,000 activities managed on a laptop and updated in seconds.
On any significant concrete project, the installation of reinforcing steel is typically on the critical path of the project. Because of this, it is important to realize that the reinforcing activity is comprised of three discrete components with a direct relationship on the timely completion of each reinforcing activity.
- 1. Detailing: The preparation of placing drawings and bar lists from the structural drawings, which convey the structural engineer’s intent.
- 2. Fabrication and delivery: The fabrication and delivery of the reinforcing that conforms to the bar lists and in accordance with the contractor’s project schedule.
- 3. Installation: The actual installation of the reinforcing steel following the contractor’s project schedule.
These activities are critical to the rebar fabricator and reinforcing contractor for the completion of their work. All have a time duration that must be considered when the project schedule is developed. General contractors and project managers should give the reinforcing fabricator and placing contractor an opportunity to have input into the schedule’s development. Having the reinforcing fabricator and contractor involved with the reinforcing and concrete portions of the schedule provides ownership of the project schedule to help avoid potential problems as construction proceeds.
By having the reinforcing fabricator and placing contractor involved, critical items—such as the location of construction joints and their sequencing—are addressed. This enables the fabricator’s detailer to ensure proper bar lengths. Fabrication and delivery issues can be coordinated properly. With concrete elements having multiple pours, such as walls, elevated decks, and beams, a clear understanding of the contractor’s plan and schedule for the excavation and forming of these elements will ensure not only the reinforcing availability, but also how the bar will fit and be supported until the concrete is poured.
Shared involvement in the schedule’s development gives all parties ownership in the plan that results in the successful development of the project’s CPM schedule, and ultimately timely project completion. Involvement with the reinforcing team members can help keep the battles to a minimum, and concrete projects from seeming like a war. Sun Tzu would be proud!