Unable to create complex formulas on excel

[Mr Kaka]

I am struggling in creating formulas that allows me to build the following table. The formulas that I need to create should be on the cells highlighted in orange.

Specifically, given:

• The number of employees on staff each month, i.e. “employees on staff”
• The number of “new tasks assigned” each month

I have to calculate following outcomes:

• number of “task completed”: task that have been accomplished, given the time to complete a task (1.5 month)
• number of “task in progress”: task that are currently been worked by the employees but that haven’t been completed yet
• number of “task to be started”: task that haven’t been worked yet. These can come from either the previous months or from the current month.

I need to create flexible formulas so that outcomes get updated by changing "employees on staff" and/or "month to complete a task" and/or "new task assigned".

 

[Mr Kaka]

Mr_excel_task_assigned.xlsx
	A	B	C	D	E	F	G	H
1
2			Month to complete a task	1.5
3
4		ID	Month	1	2	3	4
5		1	Employees on staff	1	4	5	3
6		2	New Task assigned	3	4	0	5
7		3	Task in progress	1	4
8		4	Task to be started	2	1
9		5	Task completed	0	1
10
Sheet1

Cell Formulas
Range	Formula
B6:B9	B6	=B5+1