Chapter 3 Requirements of a realistic CPM schedule

A realistic CPM schedule • The owner and its construction representatives need to determine

A realistic CPM schedule Copyright © 2009 T. L. Martin & Associates Inc.

A realistic CPM schedule The project schedule affects the management effort of the project

A realistic CPM schedule If improperly prepared, the schedule can: • Incorrectly forecast completion

A realistic CPM schedule • Define the individual tasks that make up the project.

A realistic CPM schedule • • Activity duration should be developed based on quantities

Activities • Defines the scope of work – Drawings – Estimates – Specifications •

Planning Unit (Original Duration) • PLANNING UNIT: The increment of time used to schedule

Activity Identifications (“ID”) • Alphanumeric values to define activities (individual work scopes) • Should

Type of Activity • • Work Tasks Hammock Activities or Summary Bars Milestones Flags

Activity Codes Definition - Assigned to an activity to organize them into manageable groups

Activity Codes • • Areas of the Project Phases Work Descriptions - Type of

Calendars • Define work periods when activities can start and stop • Global calendars

Calendars Other non-work periods: • Winter shut down period • Environmental shut down period

Logical Relationships • Relationships logically connect activities • Should represent the contractors proposed sequence

A realistic CPM schedule • The CPM should be developed following standard guidelines for

A realistic CPM schedule How to Assure a Quality Schedule • Allow adequate time

Please continue to Chapter 4 Standard CPM Smoke and Mirror Tricks (Manipulations) Copyright ©

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A realistic CPM schedule • The owner and its construction representatives need to determine a realistic contract performance period. – Too little time increases initial pricing and will result in contractor requests for time due to even minor changes. – Too much time (and if the contract disallows an early completion) initial pricing will be greater than necessary due to extended contractor overhead cost. • The owner incurs time related costs as delivery of the project is prolonged: – added administrative costs – lost project use costs – lost production cost, facility rent and / or duplicate space costs. Copyright © 2009 T. L. Martin & Associates Inc.

A realistic CPM schedule The project schedule affects the management effort of the project from the day it is accepted until substantial completion. If properly prepared, the schedule can: • • • Forecast completion and key project milestone Document actual progress Establish reasonable payment Predict manpower needs Determine the impact of changes Copyright © 2009 T. L. Martin & Associates Inc.

A realistic CPM schedule If improperly prepared, the schedule can: • Incorrectly forecast completion • Support overpayment • Incorrectly indicate that the owner’s actions will impact job progress • Incorrectly indicate that the contractor and/or subcontractor will impact job progress Copyright © 2009 T. L. Martin & Associates Inc.

A realistic CPM schedule • Define the individual tasks that make up the project. • Define how the tasks are related to each other. • The construction schedule should present a detailed understanding of any contract specified phasing and/or sequences of work. • Activity identification and associated quantities of work by phase or task sequence should be accurately determined. Copyright © 2009 T. L. Martin & Associates Inc.

A realistic CPM schedule • • Activity duration should be developed based on quantities of work it represents with an attainable production. – Considering estimate detail, crew make-up and anticipated man-hours and/or equipment hours per installed unit, the bid estimate represents a good measure of likely performance unique to the contractor. Activity logic and duration should include any unique requirements defined by the contract drawings and specification. Copyright © 2009 T. L. Martin & Associates Inc.

Activities • Defines the scope of work – Drawings – Estimates – Specifications • Should be based on work quantity • Separate work performed by multiple subcontractors into separate activities • Owner and contractor / subcontractor should agree to activity scope and allocated work quantities • Description - 48 characters (P 3) • Description - should contain some type of operating verb to avoid confusion Copyright © 2009 T. L. Martin & Associates Inc.

Planning Unit (Original Duration) • PLANNING UNIT: The increment of time used to schedule a project - hours, days, weeks, or months • Work starts in the morning of the (day) and finishes in the afternoon (P 3) • Duration of zero, work starts in the morning but completes in the afternoon of the previous period (P 3) • Multiple shifts cannot be defined in a work day calendar • Use hours as the planning for multiple shift operations • Maximum suggested duration for work tasks is 30 calendar days (20 work days) Copyright © 2009 T. L. Martin & Associates Inc.

Activity Identifications (“ID”) • Alphanumeric values to define activities (individual work scopes) • Should relate to areas and/or phases of the project • Assign values for “continuous flow from left to right” • Predecessor should always be lower than successor • Leave a gap in sequence • Should not change • Required for “apples to apples” comparisons • Some scheduling software change IDs and/or line numbers Copyright © 2009 T. L. Martin & Associates Inc.

Activity Codes • • Areas of the Project Phases Work Descriptions - Type of Work Responsibility Specification Section (CSI) Contract Type Blank - User defined as needed Copyright © 2009 T. L. Martin & Associates Inc.

Calendars • Define work periods when activities can start and stop • Global calendars - applied to all subsequent (base) calendars • Project Start sets 1 st day of the project in planning units • Global calendar typically should be left as a seven day work week with no holidays • Base calendar (31 possible in P 3) - typical should be five day work week with holiday • Specifications should define calendar and holidays Copyright © 2009 T. L. Martin & Associates Inc.

Calendars Other non-work periods: • Winter shut down period • Environmental shut down period • Anticipated lost weather days (sometimes defined in specification) Copyright © 2009 T. L. Martin & Associates Inc.

Logical Relationships • Relationships logically connect activities • Should represent the contractors proposed sequence of construction • Either predecessor or successor relationships • Only one activity that has no predecessor – award / notice to proceed (“NTP”) • Only one activity that has no successor - completion • Four main relationship types: – Finish to Start – Start to Start – Finish to Finish – Start to Finish Copyright © 2009 T. L. Martin & Associates Inc.

A realistic CPM schedule • The CPM should be developed following standard guidelines for useful schedules. – The schedule should depict how the project team intends to build the job. – The schedule contains one start and one ending activity. Only one activity in the schedule does not have a predecessor and only one activity does not have a successor. – The schedule should address all contract requirements. – The use of software constraints to activity timing is minimal to none. – The use of relationship leads and lags between activities is held to a minimum to none. – Activities are coded to allow easy report selection. Copyright © 2009 T. L. Martin & Associates Inc.

A realistic CPM schedule How to Assure a Quality Schedule • Allow adequate time for development review and approval • Include and/or follow a comprehensive scheduling specifications in contract requirements • Owners should not issue NTP until an accepted schedule is in place • Owner should prepare an accurate independent resource and cost estimate for the project. • Responsibility for preparing the schedule must include contractors field superintendent, subcontractors and Owner representatives. Copyright © 2009 T. L. Martin & Associates Inc.