Scheduling CTC-415

Short Interval Scheduling Plan & manage day to day activities Focus on individual activities Goal Oriented to get activity done Two Categories –Look Ahead –Production

Look Ahead Scheduling Focuses on what needs to be accomplished during next time period Extract from overall schedule More detailed than overall schedule since looking at day to day activities Must make sure that look ahead schedule matches the overall schedule

Production Scheduling Plan and Schedule one specific activity or group of sub activities related to a particular construction process Good for subcontractor work Types of schedules Date list, Bar Chart, Network Schedule Graphic Schedule, Matrix Schedule, Velocity Diagram

Production Scheduling Date List –List of Dates used to plan and manage an activity –Difficult to follow without a narrative –Can also be by hour Bar Chart –Like a regular bar chart but for sub activities

Production Scheduling Network Schedule –More complicated –More info –AON diagram Graphic Schedule –Easy to read –Several types follow

Production Scheduling Matrix Schedule –Good when identical activities with very similar sub- activities –When work is repetitive

Matrix Schedule

Production Scheduling Velocity Diagrams –Relationship between time and output –Very effective, easy to read

Velocity Diagram

Precedence Diagram Method Extension of AON Network –Allows concurrent activities to overlap –Restraints not required to model logical relationships –Schedule logic is easier and quicker to develop –Easier to modify –Better represents work flow in continuous operations

Precedence Diagram Method Disadvantages –Need to use finish to start relationships –Harder to update and manage due to reduced network detail

Precedence Diagram Method Activity Lead – Lag –Lag = time that a following activity is delayed from the start of the previous activity –Lead = time that an activity precedes the start or finish of the next activity

Precedence Diagram Method PDM Relationships –Finish to Start Like AON when no lag –Start to Start Gives a time between the current activity start and when next activity can start –Finish to Finish Gives a time between the current activity finish and when next activity can finish

Precedence Diagram Method Calculation Assumption –Once work starts it runs until complete –Activities are scheduled based on their duration –Work is not interrupted or stretched

Precedence Diagram Method Controlling Relationships –Forward pass Relationship that results in latest early finish time –Backwards pass Relationship that results in earliest late start time

Precedence Diagram Method Forward pass –Calculates the earliest time each activity in network can start and finish –Minimum project duration Backwards pass –Calculate the latest time an activity can start and finish