© Dr. Peter N. Smith. All rights reserved.
Step 1 - Creation of a Summary Table (6 columns)
The Planning stage and the first part of the Scheduling stage lead directly to the creation of this table. In fact, as Table 17.2 demonstrates, it is a tabular summary of that effort. The use of a Gantt chart can be a great assistance. In our case it permitted the determination of a more logical order of activities (compare tables 17.1 and 17.2). The six columns that comprise this table are;
Column 1: a list of activities and letter designations, preferably in order,
Column 2: a list of immediately preceding activities which must be completed,
Column 3: a list of each activity's duration (D). Use common units of time.
Columns 4, 5, & 6: leave blank for the time being
| Table 17.2: Summary of Activity Information for Garage Construction Project | ||||||
| Activity & letter designation | Duration
(Hours) |
Dependancy | (blank) | (blank) | (blank) | |
| preparation & excavation | A | 6 | - | |||
| Water & sewer hook-up | B | 8 | A | |||
| Footings & knee wall | C | 13 | A | |||
| Concrete floor | D | 10 | B, C | |||
| Stud walls & sheeting | E | 8 | C | |||
| Rough Plumbing | F | 3 | D, E | |||
| Rough electrical | G | 5 | E | |||
| Roof truss | H | 4 | E | |||
| Windows & side door | I | 3 | E | |||
| Roof deck & shingles | J | 8 | H | |||
| Aluminum siding | K | 4 | H | |||
| Wall & ceiling insulation | L | 6 | F, I, J | |||
| Garage door (electric) | M | 2 | D, G | |||
| Interior gyproc | N | 8 | L | |||
| Finish electrical | O | 3 | N | |||
| Finish Plumbing | P | 2 | N | |||
| Finish & cleanup | Q | 4 | all | |||
Step 2 - Create the network diagram.
Using the information in the First Table and the activity-on-arrow notation, one begins with event #1 and creates a network diagram that represents the logical relationship among the activities. Figure 6 is the resulting network diagram for our example. The creation of a diagram will require patience: this one required a few freehand sketches to arrange the network into its final format. In determining the network diagram, it became apparent that a dummy activity (activity Y) must exist between events 4 and 5. This activity should be added to Table 2 before proceeding, and it must be included in the following tables.
Figure 6: Activity on arrow network diagram for the garage construction project
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