#5 Tasks, sub-tasks and preceeding tasks in MS Project

We are building a model of the work activity in the computer which can be manipulated, more time or less time for specific tasks, increasing or decreasing resources,... add in cost factors,... then produce predictions of cash flow and potential profit.

This is just preliminary modeling, in reality the GC will use feedback from work in progress and previous projects to produce better predictions and target problem areas.

There is a limit to utility of fine grained task information for example;

-Concrete footings; date start, date completed.

or

-Concrete footings; establish rough grade, survey crew stake out and reference datum, excavate, test soil bearing, L&I inspector on site, set rebar, concrete slump/air entrain testing, pour concrete, protect concrete. Preceding tasks/event would be rebar shop drawings procedure and order for delivery, order concrete. Dependent tasks/events for which the concrete footings are a preceding event will be foundation walls and backfill.

The degree of information granularity will be driven by the needs of the information end user.

Information for use in the Request for Payment Voucher only requires completion or percentage completion of the item.

For a window system;

Internal GC tracking of required window system submittal materials will require dates for; contract documents provided to fabricator, fabricators shop drawing and delivery schedule, shop drawings received from fabricator, shop drawings submitted to arch/eng, shop drawing review received from arch/ eng, shop drawing review submitted to fabricator, fabricator delivery date, installation crew scheduled.

The GC's accounting system will track payments to the fabricator for shop drawings, partial payment to commence fabrication, payments for fabrication completion before shipping, payment upon deliver,... and installation crew costs.

Depending on the level of GC's management sophistication there will be an ability to predict if the task "window system" will be completed as scheduled and produce the targeted profit.

Column inputs;
MasterFormat numbers are a low priority at this time, but will be useful later for tracking items or create a link back to specification sections, if you have the time make a new excel column or change a heading on one of the columns you are not using.

Utility Trenching:
Trenching is by linear foot, same dimension for pipe or conduit length, when pricing this item as an assembly the assembly will have costs for bedding material and fill as part of the assembly.

If we cost for conduit trenching machine "DitchWitch" then it becomes a simple calculation based on machine rental with operator, installation crew and pipe or conduit material cost. A Ditch Witch type trenching machine for conduit or pipe up to about 6" diameter that can be assembled and jointed outside the trench has a cost advantage over a backhoe cut trench with 24" or 36" bucket, but large pipe sections that must be assembled and jointed in the trench will probably cost out lower with backhoe rather than the larger trenching machines. It is possible to install very large pipe with jointing outside the trench with a large trenching machine but economy of scale savings will not be present for short pipe runs or pipe runs with many lateral connections.

http://www.ditchwitch.com/trenchers-plows/heavy-duty

OSHA requires shoring of trenching more than 4ft deep for safety of workers in the trench and also for support of equipment adjacent to a trench. The type of shoring will be a function of soil type and trench width. A safe work space can be created without shoring by over excavating trench sides to produce benches at not more than 4ft vertical step, but requires more excavation, and will limit close proximity to the trench sides for large pieces of equipment. Use of DitchWitch type trenching machines reduces the need for the workforce to enter a trench.



The take-off assignment produces raw data that can be used with software to produce a base estimate, then GC will adjust with their own historical information from previous projects and call subcontractors or equipment rental companies to seek reductions in costs, reduce labor, reduce task duration time.

Assignment for Wednesday #6

Application and Certificate of Payment AIA form G702 and G703

Create an excel spreadsheet for G703 columns A through I add B2 Workforce, B3 Materials, B4 Equipment. B2 through B4 are for GC's internal use only and are not part of the Certificate for Payment:

Rows:

01 General Requirements

-Mobilization

-Erosion Control

03 Concrete

-Pads

-Light pole base

31 Earthwork

-Site Clearing

-Site Grading

-Cut and Fill

-Rip Rap

-Trenching

32 Exterior Improvements

-Asphalt Paving

-Curbs

-Striping and marking

-Fence

33 Utilities

-Potable water

-Sanitary Plumbing

-Stormwater system

Produce cost values for the above categories in B2 through B4, using National Construction Cost Estimator and unit quantities from the previous exercise. Use subtasks and assembly unit cost from the Estimator.

Coming next;
#6 Task cost estimate; workforce, materials, equipment.
#7 Task cost estimate; overhead, profit, competitive advantage
#8 Project bid cost estimate and documents required with bid
#9 Schedule of values /Project Schedule
#10 Payment voucher/cash flow

#4 Quantity Survey /Take-Off

During the bid process the GC's estimator will have prepared a quantity take-off of the construction documents.

Estimating Software including;
-Means from McGraw-Hill
-National Construction Cost Estimator from Craftsman
Provide installed assembly, material, component, equipment and workforce unit costs. The publishers base unit cost on data collected from construction industry bids and actual costs, adjusted by location with updates at each log-on to their system.

More sophisticated applications of estimating software can integrate with construction documents containing BIM tags.

For this class using the Airport Parking Facility drawings, we will be taking a less sophisticated approach;

Measure drawings to produce assembly quantities;
-Square Foot site area
-Square Foot disturbed area
-Linear foot "super silt fence"
-Linear foot temporary security fence
-Square Foot site entrance "rip-rap"
-Cubic Yard, 6" deep vegetable soil to be removed (recycle yard less than 15 miles in Trainer PA)
-Cubic Yard cut and fill on site material
-Cubic Yard imported soil material (recycled material from Trainer PA)
-Linear foot storm sewer trench cut and fill
-Linear foot storm sewer and bedding
-Quantity new manhole
-Quantity modify existing manhole
-Linear foot electric conduit and trench cut and fill
-Number of light pole footing, and light poles
-Linear foot straight curb and linear foot curved curb
-Square foot prefab structure pads
-Square foot paved area, stone base, asphalt base, asphalt wear coat, striping
-Linear foot permanent fence

The gate, entry booth and gate control system will typically be supplied and installed by a control system subcontractor, but the GC will provide power, trenching and pads.

Please review General Conditions costs in National Construction Cost Estimator, for cost that are project costs but do not represent a direct cost for construction assemblies, these costs will be reported under Mobilization and may be prorated over the proposed contract period and will include temporary facilities such as site trailer, WC, temporary utilities, installation and removal.

Storm Water Management during construction is a contract requirement and will include erection, maintenance and removal. While this item is a temporary facility it will be costed and included on the payment voucher as a separate line item.

Assume all engineering testing is by the owners team.

Coming next;
#5 MS Project 2007 assign major tasks and sub-tasks
#6 Task cost estimate; workforce, materials, equipment.
#7 Task cost estimate; overhead, profit, competitive advantage
#8 Project bid cost estimate
#9 Schedule of values /Project Schedule
#10 Payment voucher/cash flow

#3 Task Dependencies and Predeccesors

"just one thing after another"


Commencement of a work task requires preceding events or tasks to be complete.


Each preceding event or task will have sub components with their own preceding events;


Workforce and subcontractors on site for tasks

-Hire or assign GC's workforce for project and task
-Negotiate and contract subcontractors, with defined scope of work and schedule
-Daily and or weekly assignments and locations on site


Materials and equipment on site for tasks

-Supplier contracts and payment periods

-Submital procedures and critical time lines

-Delivery schedules, and crew on site to receive deliver

Testing and inspection protocol

-Negotiate and contract with engineering testing company

-Meet with public agency inspectors to confirm inspection and notification requirements

Meet with and develop relationship with;

-Public agency inspectors
-Architect or engineer of record and designated representative.
-Owners designated representative or Resident Project Representative
-Utility providers designated representative
-Funding source or sources designated representative; bank, public agency, investor,...

A preliminary project schedule can be prepared using the identified tasks, and can be modified at any time with updated task information including adding or modifying predecessors, must start and must finish dates.

Distribute preliminary contract required "major items" construction schedule.

Distribute preliminary subcontractor schedule and calender.

Distribute schedule a values to owners project team only, prepared with total value equal to the contract value as awarded, using preliminary cost estimating from the bid process and updated with information from subcontractors and material and component suppliers

During the bid process the GC's construction cost estimating team will have prepared a quantity take-off, or quantity survey, of the bid documents and prepared a line item construction cost estimate.

Once the contract value has been established in the Owner/Contractor agreement the total value or any modified may only be by change order.

Coming next;
#4 Quantity Survey
#5 MS Project 2007
#6 Task cost estimate; workforce, materials, equipment.
#7 Task cost estimate; overhead, profit, competitive advantage
#9 Project bid cost estimate
#10 Schedule of values /Project Schedule
#11 Payment voucher/cash flow

The assignment for Monday July 13, 2009 due by email midnight Sunday July 12, 2009;

Assume all work is by subcontractor, use the drawing set and Construction Specifiers Institute Format to break the work down to major tasks and sub-tasks within those major tasks, then allocate work tasks to sub contractors, then create a scope of work for each subcontractor.

Insert the task information into MS Project 2007 and assign predecessors to each task.

In the following week we will use National Construction Cost Estimator 2007 to assign cost values to those tasks including; workforce, materials and components, equipment, overhead, profit and competitive advantage.

You can work with a partner, but submit your work separately and identify your partner.

Read Construction Project Management 3rd Edition by Gould and Joyce Chapter 9 and 10.

#2 Define work by task part 2

Airport Parking Site Major tasks;

Temporary Facilities and Controls are items and tasks that are not part of the permanent installation. Usually organized at Division 01 in the CSI format;

-Site security Fence

-Storm water, erosion and sedimentation controls during construction

-Temporary utilities during construction

-Survey and layout

-Engineering testing during construction

-Site office trailer and WC

-Site janitorial and waste management

-Close-out procedures

Site work (CSI division 02); preparation or taking the site from existing condition to ready for new work, which may include; demolition, removing trees, removing vegetable soils and rough grade. Usually organized at division 02 in the CSI format; -Rough grade including permanent storm water retention swales, to reference datum establish by survey/layout crew.

-Haul and dispose of excavated material to be removed from the site, cut and fill will require some of the clean excavated material to be stock-piled on site.

-Import, place and compact engineered fill material to achieve design subgrade for paving system.

-Excavate for utility trenching including back-fill and compaction.

-Excavation and preparation including base materials for concrete curbs, pads and footings.

-Asphaltic Paving system including supply and placement.

-Paving stripping.

Concrete (CSI division 03); work will include placing and striking formwork, reinforcing bar and mat supply and placement, concrete supply, placement and finish, protection of concrete in place.

Metals (CSI division 05); work will include supply and install permanent fence system, the fence contractor will be responsible for supplying fence post hole auger and concrete.

Sub-Grade utilities;

Storm and Sanitary plumbing (CSI division 22), including supply and install; pipe, inlets, manholes,...

Electric supply and distribution (CSI division 26), including service connection, distribution panel, conduit, distribution, light poles,...

Prefab security booth and gate system (CSI division 13), including supply and install including control system wiring.

Landscaping (CSI division 32), including supply and install topsoil, mulch, plant materials and one year maintenance for plant material establishment.

Sample Scope of Work for Curbing Subcontractor;

Refer to attached drawing set Dated --/--/----;

Provide all materials, equipment and manpower required for complete installation of curbing as shown on the drawing set.

Coordinate with excavation contractor for preparation of curbing sub-base and backfill.

Coordinate with survey layout crew for curb location, curved curbs and top of curb elevation.

Coordinate with engineering testing field inspector for specification conformance of concrete, formwork, finish quality, control joints and expansion joints.

Coming next;

#3 Task Dependencies

#4 Quantity Survey

#5 MS Project 2007

#6 Task cost estimate; workforce, materials, equipment.

#7 Task cost estimate; overhead, profit, competitive advantage

#9 Project bid cost estimate

#10 Schedule of values /Project Schedule

#11 Payment voucher/cash flow

#1 Define Work by Major Task

The construction process is "just one thing after another"

All the things that make up a construction process can be be defined as tasks;

-Site clearing
-Foundation system
-Structural system
-Exterior wall systems
-Roofing Systems
-Interior finishes,...

Each task can be further broken down to sub-tasks within a larger task and the tasks can be allocated to the individual trades and subcontractors.

Construction cost estimates may be defined by the intended end use;
-Preliminary cost estimate for owner budget development, usually prepared by the design architect or engineer based on historical square foot cost data for similar projects and may be presented as range high-average-low.

-Design development cost estimate for owner budget development, prepared by the design architect or engineer, or by the owners construction manager, or estimating consultant; based on historical cost data and applied to the project for construction type, components and quantities.

-General Contractor bid proposal, prepared by the general contractors bid team and or an estimating consultant; using industry historic cost data, subcontractors and suppliers preliminary proposals to the GC, and the general contractors in house historical cost data on similar projects. The general contractor will then apply multiplier factors to the cost estimate to account for overhead costs, profit target, and bid competition.
Adjustment may be made up or down for known history within the industry of working with the particular owner, architect, engineer, construction manager, regulator authority,...

-The General Contractor upon being awarded the contract will prepare a preliminary project schedule and schedule of values for review by the owner project team which may include architect, engineer and construction manager. In preparing the bid the GC will have blocked out a preliminary schedule and reviewed sub-tasks within the schedule with subcontractors and suppliers for availability of resources.

The assignment for Monday July 13, 2009 due by email midnight Sunday July 12, 2009;

Assume all work is by subcontractor, use the drawing set and Construction Specifiers Institute Format to break the work down to major tasks and sub-tasks within those major tasks, then allocate work tasks to sub contractors, then create a scope of work for each subcontractor. Insert the task information into MS Project 2007 and assign dependencies to each task.

In the following week we will use National Construction Cost Estimator 2007 to assign cost values to those tasks including; workforce, materials and components, equipment, overhead, profit and competitive advantage.

You can work with a partner, but submit your work separately and identify your partner.

Read Construction Project Management 3rd Edition by Gould and Joyce Chapter 9 and 10.