# formula to caculate depedancies and start dates?

#### tonywatsonhelp

##### Well-known Member
Hi Everyone,
I'm putting toghther a very simple Gantt chart for a project.
I have 6 different parts to the project.
each part is seperated by a Project Number
so project 1 has 1, 1.1, 1.2, 1.3 etc.
The project numbers are in Column C
In Column D I have start date of the projects and in Column E the duration (not including weekends)
I want to caculate the actual start date of each part?

so heres my problem,
how can I caculate the start dates and end dates for each part? (Taking into account weekends not worked)

Below is a small example of what I have as I think visual will help.

 A B C D E F G H I J K L M N 1 PROJECT NAME PROJECT NUMBER START DATE OF PROJECT DURRATION ACTUAL START DATE END DATE 2 Tony 1 1 1/1/19 5 1/1/19 5/1/19 3 tony1 dependency 1 1.1 5 6/1/19 11/1/19 4 tony1 dependency 2​ 1.2 2 12/1/19 14/1/19 5 tony1 dependency 3​ 1.3 3 15/1/19 18/1/19 6 Tony 2 2 3/1/19 10 3/1/19 13/1/19 7 tony2 dependency 2​ 2.1 5 14/1/19 19/1/19 8 tony2 dependency 1​ 2.1 8 14/1/19 22/1/19 9 tony1 dependency 4​ 1.3 2 15/1/19 17/1/19 10 11 12 13 14 15 16 17 18 19

<tbody>
</tbody>

so hopefully above you can see what I need to caculate,
my example dose not take into accpunt weekdays but should,
I can add extra columns if need be.
as you can see the parts wont allways follow each other so a part of project 1 can show up after project 2 and there can be more than one 1.1 for example but this would only happen if there was no number after it.

thanks
Tony

### Excel Facts

Which lookup functions find a value equal or greater than the lookup value?
MATCH uses -1 to find larger value (lookup table must be sorted ZA). XLOOKUP uses 1 to find values greater and does not need to be sorted.

#### Drrellik

##### Well-known Member
Actual Start Date is in column F if you are calculating F what data are you using? the end date minus duration? not sure what you are trying to populate based on a formula

~DR

Replies
19
Views
241
Replies
4
Views
46
Replies
1
Views
153
Replies
4
Views
33
Replies
18
Views
133