Task   | Start Date  | End Date   | Predes.| Resource |Duration
------------------------------------------------------------------------
Task1 | 17-Aug-09 | 17-Aug-09 |            | R1         | 1 Day

Task2 | 17-Aug-09 | 19-Aug-09 |    1SS   | R2         | 3 Day

Task3 | 18-Aug-09 | 19-Aug-09|     1       | R1        | 2 Day

Task4 | 20-Aug-09 | 20-Aug-09|     3       | R2        | 1 Day



In this scenario when R1 completes task3 in 1 day then Task4 Start Date will change to 19-Aug-09. Where as actually R2 will be engaged from 17-Aug-09 to 19-Aug-09 in Task2. Which means R2 cannot work on 2 task simultaneously. How can I avoid such situation.



NB: All task type are created as Fixed Duration

Software/Hardware used:
MS Project