Código fuente laboratorio de filtros digitales

Figure 4.7 shows a bar chart created with Excel that leaves room to update the project with the actual start and finish dates. The actual bars could be entered by hand with a highlight- ing marker. Also notice the weekends and holidays are shaded to show them as nonwork days. This bar chart shows only a portion of the complete schedule. Refer to the CD included with the text under the file name Bar Chart Example.xls to see the complete schedule. It could be used to create bar charts for commercial, industrial, residential, or highway projects.

The bar chart schedule illustrated in Figure 4.8 details construction of the first floor of a hotel. It was created with the use of SureTrak Project Manager, a dedicated project management software program.

In Figure 4.9 you can see a portion of a bar chart schedule for a highway overpass. Primavera Project Planner, another dedicated project management software program, was used to create the schedule.

Month July August Calendar Date

Work Day

Survey

Install Temp. Power Excavate FRIP Footings Termite Treatment FRIPS Foundation Strip, WP & Plstr. Fdn. Cure Foundation Plumb Sub Slab Inst. Window Wells Form Bsmt. Slab Back Fill & Rough Grade Pour Basement Slab Settle Foundation Soil Frame & Install Windows Final Grade Exterior Concrete Install Roofing Rough HVAC Rough Plumbing Masonry Rough Electrical 4-Way Inspection Wall Insulation Exterior Trim 1 2 3 4 5 6 7 8 9 1011 121314 15 16 17 1819 20 21 2223 24 25 2627 28 2930 31 1 2 3 4 5 6 7 8 9 101112 13 14 1516 1 2 3 H 4 WW5 6 7 8 9 W W1011 121314W W15 16 17 1819W W20 21 22 23 24 W W25 2627 28 29W W30 3132 33 34

Chapter 4 • Bar Chart Schedules 35

FIGURE 4.8 Bar chart created using SureTrak Project Manager

Conclusion

Advantages of bar charts:

• The proper use of bar charts can make them a powerful management tool. • The total management team can look at the

bar chart and get the vision or big picture of the job.

• The bar chart forces the management team to think and plan the project in

detail and it enables them to control the project and communicate that plan to all involved.

• A bar chart is the familiar and accepted schedule for most field personnel.

• It gives a visual or graphic representation of the process of construction, which helps the management team, as well as the field

FIGURE 4.9 Bar chart created using Primavera Project Planner

workers, see what is planned and when activities should happen.

• A bar chart provides a goal to work toward. • A bar chart can be used to measure

progress and performance. Disadvantages of bar charts:

• The bar chart does not automatically show the effects of changes. The manager

must rethink and redraw the schedule continually.

• The bar chart also does not help the man- ager identify the critical activities that determine the completion date of the proj- ect. However, intuition tells experienced managers which project activities are not urgent and which are critical and must be done on the days specified.

Chapter 4 • Bar Chart Schedules 37

• It is very difficult, if not impossible, with a bar chart to see the effects of a change and whether or not a potential change will affect the project completion date. This becomes a point of contention between the

owner and the contractor when changes are proposed.

• Most of the disadvantages are resolved with bar charts based on CPM schedules, as is discussed in the following chapters.

Application

1. If you are currently working on a project, using Excel or graph paper create a bar chart schedule for the remainder of that project, or at least for the next three months. Make it into a bar chart that can easily be updated to show the actual schedule compared to the as-planned schedule. If you are not currently working on a project, do activity 2.

2. You have been asked by your boss to cre- ate a first draft bar chart that will be used in a presentation for a negotiated contract for the construction of a warehouse. Using Excel or a piece of graph paper create an impressive bar chart schedule that will be included in the proposal to the owner. The owner has furnished the following brief scope of work. Fill in other details as needed. The detailed plans will be devel- oped later. The warehouse is 40 ×120 feet, with a concrete footing and floor slab. It is

a steel structure with the sections between the structural posts filled in with metal studs. It has exterior insulation finish sys- tem (EIFS) exterior wall coverings. The roofing material is a single-ply roof mem- brane. The roof is insulated with fiberglass insulation on the inside, with a heavy plastic protection on the bottom side of the insulation. The exterior walls will be insulated with fiberglass batts. The only interior partitions are for a small office and restrooms. The inside wall coverings are drywall that will be finished and painted. The heating system consists of natural gas unit heaters suspended from the ceiling. There is no cooling system. There are two large overhead doors and two man doors for access to the building. There are also some landscaping and paved parking areas around the building.

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INTRODUCTION

This chapter introduces the critical path method (CPM) of planning and scheduling. It explains the advantages of CPM as compared to other scheduling methods, and discusses why so many sophisticated project managers prefer CPM and consistently use it to help manage construction projects.