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Unformatted text preview: developed in order to show more information: Node numbers showing order of activities shown in the left hand semicircle of each node 1 The right hand quarters will be used to hold additional information © Business Studies Online: Slide 5 Calculating The Earliest Start Time The main reason for drawing a network is to identify the CRITICAL activities To do this we must calculate the earliest time at which any given activity can start This is called the Earliest Start Time (EST) of the activity It is calculated using the following formula: EST = EST of Previous activity + Duration of previous activity © Business Studies Online: Slide 6 Calculating The Earliest Start Time This information is then placed in the top righthand EST goes in quarter of the node top right 0 hand The first node will ALWAYS 1 quarter of have an EST of zero the node Using our first simple example, the EST for each activity would be calculated as follows: 1 0 A + 12 = 12 2 B + 3 = 15 3 © Business Studies Online: Slide 7 The EST and Simultaneous Activities When there are simultaneous activities there may be more than one value for the EST A Eg: 12 + 12 = B 1 0 2 AA + 14 = 17 + 3 = 3 14 Since Activity B is DEPENDENT on both Activities A and AA, it cannot start until both are complete So we must take the HIGHEST figure This means that the EST is 14 weeks © Business Studies Online: Slide 8 Recap of The Earliest Start Time Re
The EST of the first activity is always zero Calculate the EST by working left to right across a network It is calculated using the following formula: EST = EST of Previous activity + Duration of previous activity When there are 2 simultaneous activities the HIGHEST figure is used as the EST © Business Studies Online: Slid...
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- Winter '14