Have a SUM(Field_1) not exceed SUM(Field_2) - sql

Question

There might be a better way to accomplish but here is what I have:
Environment - Plex ERP -SQL Query Editor
Back-end - SQL Server 2012
Summary
Parts have a "unit" worth based on manufacturing complexity
Some days we ship part\s. Other days we don't
The part units are summed for each day they are scheduled to ship 'Rel_Units_Calc'
The plant gets credit for 5 units a day (when open) 'Unit_multiplier'
This daily credit is summed for each day 'Unit_Capacity'
In order to prevent an overloading of capacity in a slow month, I need to prevent the plant from getting the 5 unit credit when the SUM(Unit_Capacity) will exceed the SUM(Rel_Units_Calc).
A report will be created that will use a case statement to evaluate if the Rel_Units_Calc > Unit_Capcity, then show red else green.
Detailed Scope
I'm trying to create a sales report that will prevent the sales group from overloading (exceeding the capacity) of the plant. To simplify, lets say we have 3 parts (Part A, B, & C). Part A is simple and worth 1 "Unit". Part B is a little more complex and worth 2 "Units". Part C is the most complex and worth 5 "Units". The plant can process 5 units a day that it is open.
The report will show when a day has been overloaded by showing the color Red and green when days are not overloaded. Any days in red will need to have the sales order moved out.
My approach was to take the units * order quantity to give me the 'Release_Units'. Then I am doing a sum(Release_Units) to show a tally for each day in a field called 'Release_Units_Calc'.
I have another field called 'Unit_Multiplier' that gives the 5 unit per day credit on eligible days (excludes weekends and holidays). Then I am doing a sum(Unit_Multiplier) to show a tally for each day in a field called 'Unit_Capacity'.
The color Red and Green were going to be determined by using a case statement comparing the two columns Release_Units_Calc and Unit_Capacity. When Unit_capacity = Release_Unit then green else red.
This works ok until you look at December when we have a slow down for these parts and then we start banking Unit_Capacity. The Unit_Capacity field continues to accrue the 5 units per day even after it has surpassed the Release_Units_Calc. These parts are not produced in December so think 20 business days * 5 units per day gives us 100 Units on Jan 1 which is not good. Essentially, this would cause the sales group to overwhelm the plant in January as they will have 100 banked units to draw from.
I would like for the Unit_Capacity which again, is a SUM(Unit_Multiplier) to not exceed the Release_Units_Calc which is from SUM(Release_Units).
SQL Below:
This temp table marks the days that should be included for the capacity
SELECT
DISTINCT FDPO.FULL_DATE,
----case statement below to create an include flag. It will exclude weekends unless we have a shipment going out
(CASE WHEN (DATENAME(dw, DATEADD(d,0,FDPO.Full_Date)) NOT IN
('Saturday','Sunday')) THEN 1
WHEN (DATENAME(dw, DATEADD(d,0,FDPO.Full_Date)) IN
('Saturday','Sunday')) AND FDPO.DUE_DATE IS NOT NULL THEN 1
ELSE 0 END) AS 'Include'
INTO #Capacity_Temp1
FROM #FDPO AS FDPO
This temp table uses the include flag to remove the dates that should not accrue capacity and adds a capacity column.
SELECT
CT1.FULL_DATE,
#Unit_Multiplier AS 'Unit_multiplier'
INTO #Capacity_Temp2
FROM #Capacity_Temp1 AS ct1
WHERE ct1.INCLUDE= 1
The temp table below adds the unit multiplier up for each day
SELECT
DISTINCT CT2.FULL_DATE,
CT2.Unit_multiplier,
SUM(CT2.Unit_multiplier) OVER (Order By CT2.FULL_DATE) AS 'Unit_Capacity'
INTO #Unit_Capacity
FROM #Capacity_Temp2 AS CT2
The final display query
SELECT
RUC.FULL_DATE,
RUC.Release_Units,
RUC.Release_Units_Calc,--running talley of the release units
ISNULL(UC.Unit_multiplier,0) AS 'Unit_multiplier',
-- credit units given per day except when closed
UC.Unit_Capacity --running talley of the unit multiplier
FROM #RUC AS RUC
LEFT JOIN #Unit_Capacity AS UC
ON UC.FULL_DATE = RUC.FULL_DATE
The output at present:
╔══════╦═══════════════╦════════════════╦═════════════════╦═══════════════╗
║ DATE ║ Release_Units ║ Rel_Units_Calc ║ Unit_multiplier ║ Unit_Capacity ║
╠══════╬═══════════════╬════════════════╬═════════════════╬═══════════════╣
║ 8/3 ║ 15 ║ 15 ║ 5 ║ 5 ║
║ 8/4 ║ NULL ║ 15 ║ 5 ║ 10 ║
║ 8/5 ║ 20 ║ 50 ║ 5 ║ 15 ║
║ 8/5 ║ 15 ║ 50 ║ 5 ║ 15 ║
║ 8/6 ║ NULL ║ 50 ║ 0 ║ NULL ║
║ 8/7 ║ NULL ║ 50 ║ 5 ║ 20 ║
║ 8/8 ║ NULL ║ 50 ║ 5 ║ 25 ║
║ 8/9 ║ NULL ║ 50 ║ 5 ║ 30 ║
║ 8/10 ║ NULL ║ 50 ║ 5 ║ 35 ║
║ 8/11 ║ NULL ║ 50 ║ 5 ║ 40 ║
║ 8/12 ║ 15 ║ 65 ║ 5 ║ 45 ║
║ 8/13 ║ NULL ║ 65 ║ 0 ║ NULL ║
║ 8/14 ║ NULL ║ 65 ║ 5 ║ 50 ║
║ 8/15 ║ NULL ║ 65 ║ 5 ║ 55 ║
║ 8/16 ║ 10 ║ 75 ║ 5 ║ 60 ║
║ 8/17 ║ NULL ║ 75 ║ 5 ║ 65 ║
║ 8/18 ║ NULL ║ 75 ║ 5 ║ 70 ║
║ 8/19 ║ NULL ║ 75 ║ 0 ║ NULL ║
║ 8/20 ║ NULL ║ 75 ║ 0 ║ NULL ║
║ 8/21 ║ NULL ║ 75 ║ 5 ║ 75 ║
║ 8/22 ║ NULL ║ 75 ║ 5 ║ 80 ║
║ 8/23 ║ NULL ║ 75 ║ 5 ║ 85 ║
║ 8/24 ║ NULL ║ 75 ║ 5 ║ 90 ║
║ 8/25 ║ NULL ║ 75 ║ 5 ║ 95 ║
║ 8/26 ║ 10 ║ 95 ║ 5 ║ 100 ║
║ 8/27 ║ 10 ║ 95 ║ 5 ║ 105 ║
╚══════╩═══════════════╩════════════════╩═════════════════╩═══════════════╝
The problem occurs on 8/22 where we start to exceed the Rel_Units_Calc field. This allows an order to be placed on 8/27 that will not trigger the Red because the Unit_Capacity will be greater than the Rel_Units_Calc.
Sorry for the long post. I'm open to any suggestions if there is a better way to accomplish this.
Thanks in Advance,
Mike