[Year 12 IT Apps] information needed for gantt charts

[Timmer-Arends]

Since everybody else is having a go....

"A lead is a forced wait before a task can commence; eg scheduling a Post Implementation Review on a project for two weeks after the installation date. There may be no intervening activity planned, but we have to wait anyway"

"A lag is a forced wait after an activity before an event can occur; eg you might throw a concrete floor and then have to wait three days for it to cure before laying it with tiles"

"the slack time for an event is given by subtracting its earliest time from its latest time. This is a measure of the delay which the event could suffer ...and still allow the project to finish within the original estimate range"

"The float time is the amount of time that a task start could be delayed without affecting the date upon which the succeeding event would occur

"Managing Information Technology Projects", McLeod and Smith (University of Cape Town), Course Technology, 1996

...and then there is the question of how deeply does one have to go into all of this anyway?


Regards
Robert T-A
Brighton SC

----- Original Message ----- 
  From: PARAGREEN, Chris 
  To: Year 12 IT Applications Teachers' Mailing List 
  Sent: Thursday, March 05, 2009 12:36 PM
  Subject: RE: [Year 12 IT Apps] information needed for gantt charts


  My first post as a newbie IT teacher!

   

  "Just" a question about some of the definitions for Gantt charts..

  According to Potts (p30), lead time is, ". time leading up to or before a task." It further explains the concept, but essentially this is it.

  My understanding is that lead time is the time available to begin a dependant task before its predecessor is finished.

  For example, you can't set up a computer until the box has arrived, but you can prepare the room in advance.

   

  Similarly, Potts states that slack time and lag time are the same thing, whereas I think they are not.

  Slack is the available time to allow for delays, but lag is the time between when a task finishes and when it's dependant task can begin.

  For example, if pouring concrete, the actually pouring task might have finished, but you have to wait for the concrete to cure (the lag time) before you can paint it.

   

  Are my definitions too precise for what we need to teach, am I wrong, or am I missing something?

   

  Regards,

   

   

  Chris Paragreen

  IT, Mathematics and Japanese Teacher and Timetabler

  Kew High School

  1393 Burke Road

  Kew East VIC 3102

  phone +613 9859 8652 fax +613 9819 7880

  chris.paragreen at kew.vic.edu.au

  2008 International Year of Languages 

  Languages Still Matter! 

   

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