Agenda. CPM Scheduling at CDOT Laura Zamora, P.E. February 24, 2016

Transcription

1 CPM Scheduling at CDOT Laura Zamora, P.E. February 24, 2016 Agenda Revision of Schedule How CDOT Uses Construction Schedules Critical Path Method Scheduling Microsoft Project Overview 1

2 Revision of Schedule Purpose for the change is to ensure we receive realistic and complete schedules to jointly manage the work and evaluate delays Define float ownership Revision of Schedule Provide clear requirements on submittals and review times Provide tools for Project Staff to analyze submittals Provide tools for analyzing changes Improve consistency 2

3 How we got here: Task Force included members from: CDOT CCA Kraemer Hamon SEMA Castle Rock Concrete Express HDR Atkins Trauner CDOT and Consultants started meeting in December 2012 CDOT, Consultants, and CCA started meeting in September 2013 Spec was issued July 31, 2014 Guidance Issued February 2015 Summary of Changes Address Early Completion Schedules Get a good schedule before work starts ECS will require more detail on production rates We need to get better at developing contract time Use Innovative Contracting tools when appropriate 3

4 Summary of Changes - Approval Require an Approved Preliminary OR Baseline Schedule BEFORE work starts Float is defined owned by Project Approval - Added the requirement for approval (3-levels) Approved Approved with comments Revise and resubmit Summary of Changes - Reporting Reporting/Practices/Logic/Changes are defined to allow for best schedule practices No negative lags, start to finish relationships, openended activities Lags >10 work days and constraints must be explained Job Progress Narrative Reports: Predecessor and Successor Activity Early Start Float Critical Path List of non-workdays 4

5 Summary of Changes - Other Method Statements for Salient Features or as directed by the Engineer Scheduling software requirements remain the same Primavera or MS Project Bar Charts are not allowed Next Steps Guidance in CDOT Construction Manual Workshops/Outreach Survey conducted late 2015 Update CDOT Training - FY 16 Improve development of Contract time 5

6 How CDOT uses Schedules If plan meets the contract requirements Check that milestones will meet Contract requirements Added or deleted, how it affects the remaining work Delays occur, determine how much additional time is needed Determine when money will be spent Critical Path Method Scheduling Critical Path Method - CPM - a method of calculating project s total duration based on activity durations and their dependencies 6

7 Critical Path Method Scheduling Critical Path Is the longest path in the schedule. Critical Path Scheduling: Identifies the Most Important Tasks Helps Reduce Timelines Compares Planned with Actual Critical Path Method Scheduling Critical Task A task that must be completed on schedule for the project to finish on time. If a critical task is delayed, the project finish date might also be delayed. 7

8 Critical Path Method Scheduling Total Float The amount of time an activity can be delayed without delaying the entire project. Free Float The amount of time an activity can be delayed without delaying a successor activity. MS Project uses the term Slack Critical Path Method Scheduling Baseline Schedule - A snapshot of your schedule at a pint in time and includes information about tasks, resources, and assignments. Doesn t change unless Initial Schedule Schedule Updates 8

9 Bar Charts CDOT does not allow bar charts for design or construction schedules because: Can t be used to analyze the impact of changes A Bar Chart does not show dependencies Of the Bar Chart s inability to show float A Bar Chart does not indicate which activities are critical Steps to Planning CPM is a Tool to help plan your project o Scope > List of tasks o Time > Durations of tasks o Cost > Resources required to complete tasks o Resources > Who / what / when needed for tasks o Communication > Clear logical timeline of project o Quality > Increased understanding of task coordination for successful delivery of project o Risk > Identify critical path / tasks which could impact delivery of project 9

10 Steps to Develop a Schedule Four principle workflow elements Tasks Duration Relationships Resources Relationships Predecessors Successors Keys to Accurate CPM 10

11 FS Finish to Start Relationship Types Predecessor s finish determines successor s start. Most common, default setting SS Start to Start Predecessor s start determines successor s start. Concurrent start dates on linked tasks FF Finish to Finish Relationship Types Predecessor s finish determines successor s finish. SF Start to Finish Not allowed by CDOT Predecessor s start determines successor s finish. 11

12 Relationship Types Lag creates a delay between two tasks that share a dependency Lead (Negative Lag) Not allowed by CDOT is an overlap between two tasks that share a dependency Question Your Linkages Does a task need to start/end on an exact date? Does a task need to be done before, or after, another task? Can a task overlap another task? Will you build in slack/float for this task? If so, it cannot be part of the Critical Path. 12

13 Keys to Accurate CPM Constraints - should be minimized As Soon As Possible (default) Finish No Earlier Than or Finish No Later Than* Must Start On* or Must Finish On* Start No Earlier Than* or Start No Later Than* * Require Engineer approval Identifying Critical Path Why is the Critical Path important? Detail Gantt view 13

14 Microsoft Project Layout Ribbon Menu Timeline Subgroups Table Area Gantt Chart Area Project Basic Functions Ribbon Menu File Tab Task Tab Resource Tab Project Tab View Tab Acrobat Tab Format Tab Each tab is organized into sub groups for easy navigation. 14

15 Table Area Gantt Chart Area Milestone Summary Bars Timescale 15

16 Working with MSP Calendars Standard calendar Monday -Friday 8am-5pm 20 days/month Project schedules do not always fit the standard calendar Customizing the Gantt Chart Creating personalized Gantt Chart Views 16

17 Displaying Task Names Customizing the Gantt Chart Customizing the Gantt Chart Creating personalized Tables 17

18 Changing Calendar top view Customizing the Gantt Chart Customizing the Gantt Chart Use the Organizer to transfer personalized formatting 18

19 Changing Schedule Dates Set the Project Start Date Modify calendar constraints Baseline Schedules 19

20 Questions? Thank you! Area Engineers Laura Zamora (303) Mark Straub Kevin Ryburn Roselle Drahushak-Crow Frank Kinder 20