Calculating weeks on hand based on forecast of subsequent weeks

Prajju

Hi,

 

I have the following dataset:

 

Item	Date	Projected Inventory(PE)	Forecast(FC)
A	Jan 28, 2019	604	50
A	Feb 04, 2019	630	52
A	Feb 11, 2019	1303	49
A	Feb 18, 2019	1257	46
A	Feb 25, 2019	1176	51
A	Mar 04, 2019	1136	55
A	Mar 11, 2019	1083	53
A	Mar 18, 2019	1030	53
A	Mar 25, 2019	980	50
A	Apr 01, 2019	900	65
A	Apr 08, 2019	853	62
A	Apr 15, 2019	944	59
A	Apr 22, 2019	1303	49

 

The Desired O/ P is:

Item	Date	Weeks On Hand
A	Jan 28, 2019	11
A	Feb 04, 2019	12
A.	Feb 11, 2019	9
A	Feb 18, 2019	8
A	Feb 24, 2019	0 (there should be at least 10 weeks of Forecast for an item , if not the WOH = 0)
A	...	0

 

The logic is as follows:

I need to calculate the number of weeks on hand for each item for that particular week based on forecast for several weeks going forward.

So  for week of Jan 28, 2019 , the Projected Inventory is 604.

In order to calculate the Weeks On hand of Item A for week of Jan 28, 2019 the calculation is as follows:

 

FOR WEEK OF Jan 28, 2019:

 

Iteration 1:

 

604 – 50(FC for week 1) = 554

Weeks on Hand(WOH)  = 0 + 1 = 1

 

Iteration 2:

554 – 52(FC for week 2) = 502

WOH = 1 + 1 = 2

 

Iteration 3:

502 – 49 (FC for week 3) = 453

WOH = 2 + 1 = 3

 And so on…

 

Finally we get WOH = 11  for Item A for week of Jan 28, 2019.

 

FOR WEEK OF Feb,04 2019:

 

Iteration 1:

 

650 – 52(FC for week 2) = 598

Weeks on Hand(WOH)  = 0 + 1 = 1

 

Iteration 2:

598 – 49(FC for week 2) = 549

WOH = 1 + 1 = 2

 

Iteration 3:

549 – 46 (FC for week 3) = 503

WOH = 2 + 1 = 3

 And so on…

 

Finally we get WOH = 12  for Item A for week of Feb 04, 2019.

 

 

Similarly I need to calculate WOH for subsequent weeks and for different items

NOTE: Also there should be at least 10 weeks of Forecast for an item , if not the WOH = 0.

 

How to achieve this result in My SQL?

I am thinking Stored Procedures using cursors is the way to go. However I am not really familiar with Stored Procedure.

Is there an alternate method ? Any help will be appreciated.

 

Thanks in advance.

Prajwal

ST_-Superman-_

Do you have access to Redshift?  Or does it need to be a MySQL dataflow?

Prajju

I have access to Redshift, yes. It does not necessarily have to be MySQL dataflow.

ST_-Superman-_

I'll try to work on this tomorrow.  Can I get an idea of how many Items are in your data set?  Are you also forecasting for multiple locations?

Prajju

There are a total of 1172 Items , but all Locations aggregated for an item. So basically just 1 location.

For each item there are upto 72 weeks of data so the dataset has a total of 84K+ rows.

Thanks.

Prajju

Could someone help me out with this or provide me with some direction?

 

Thanks in advance.