Start Period and End Period Calculation

[makarand]

Hello gyys,

I want to create two variables Start_Period and End_Period like shown in below

Start_Period= End_Period (prev value for respective project)

End_Period = Start_Period + New_Cust - Cust_Left

What I have is Month Project New_Cust Cust_Left

what I need to do is Start_Period and End_Period

Month	Project	Start_Period	New_Cust	Cust_Left	End_Period	periodCalc
11-Apr	a	0	131	22	109	0.201835
11-May	a	109	70	85	94	0.904255
11-Jun	b	94	55	70	79	0.886076
11-Jul	a	79	79	63	95	0.663158
11-Aug	a	95	154	96	153	0.627451
11-Sep	b	153	185	90	248	0.362903
11-Oct	aa	248	181	103	326	0.315951
11-Nov	a	326	161	114	373	0.30563
11-Dec	s	373	231	97	507	0.191321
12-Jan	a	507	183	86	604	0.142384

Any help would be highly appriciated.

Thanks in advance.

Mac

[RahulG]

It seems you want to solve your assignment posting multiple questions.

Whats the problem are you facing to solve it. It's very straight forward calculation.

As a hint for start date.. read about retain or lag function.

[makarand]

Thanks RahulG,
but we don't have lag or retain function in VA.. so I'm not able to do it as you helped on other question.