Manually Editing Buffer Profiles

Buffer Profile review should ideally take place every few months. You will want to monitor your buffer profiles to ensure that they are large enough to protect you from stocking out while still small enough to ensure you aren't ordering too much or holding too much inventory.

Buffer profile review does not need to be strict. The idea of DDMRP buffers is to be roughly right, not precisely wrong. However, you do want to ensure that you are tracking buffer performance and making changes to the buffer profile where necessary and doing a rerun of the Smart Buffer Profiler every few months.

The steps to running the Smart Buffer Profiler to set buffer profiles can be found in the Buffer Creation & Management pages. The steps on this page will cover how to manually change buffer profiles, including how to set up a Min Max and Replenished Override Buffer profile.

Changing a Buffer Profile on a Part

To change a Buffer Profile on a part, you will need to access that part's Part record. You can do this either through the Part Editor or through the Workbench Preview part details screens.

Once you are on the Edit tab of the Part record, click on the Inventory Planning dropdown under the "Inventory Management" section of the record. In the dropdown, scroll down to or type in the buffer profile that you want to change the part to. Make sure you are selecting a buffer profile in the same location as the part.

Once you select that buffer profile, the buffer profile measurements on the part record will change to reflect the new profile. This will allow you to test to see if the new buffer profile looks the way you want it to. Once you have confirmed that the correct buffer has been selected, click the "Save" button in the lower right hand corner of the screen.

Changing to a Min-Max Buffer Type

There are certain instances in which you may want to change your part to a Min-Max profile instead of using a typical buffer. You will be able to use the same dropdown menu in the Part record to convert the part to a Min-Max. Instead of selecting a new buffer, scroll to the top of the dropdown and select the "MM" option. The buffer will disappear, leaving you to enter the values of the green and red zones.

Green Zone Requirements for MM

The Min-Max buffer will still follow the same guidelines as a regular buffer in that it will issue a recommended reorder quantity when the Net Flow enters the Red Zone of the MM buffer. This means that the Green Zone should follow the same logic as a regular buffer's green zone. This means that it should often either be the MOQ or the Order Cycle Day x EDU. Like a normal buffer, it is recommended that you use whichever is the largest.

Red Zone Requirements for MM

The Red Zone should be treated a little different than the Red Zone of a typical buffer.

The first way to think about the Red Zone of a MM buffer is that it is the "safety stock" or minimum amount that you would like to have on hand for this part at all times. However, it's often difficult to know if the safety stock numbers you currently use - if any - are still applicable to the MM equation.

The traditional way to calculate the Red Zone in the MM buffer is by substituting in the Yellow Zone calculation and also adding in the Red Zone Safety from the regular buffer. This calculation is:

(ADU x RPlus Lead Time) + (ADU x RPlus Lead Time x Variability Factor)

The variability factor to use for this calculation is the value assigned to a "3" variability factor setting in a typical buffer profile. If you have an order multiple, you should round the calculated number up to the nearest number divisible by the Order Multiple. This is a good baseline to determine a strong Red Zone for a MM profile.

Entering the Green and Red Zone Values

Once you have determined the Red and Green Zone values that you wish to use, it is time to enter the right values into the MM settings in the Part record. When you set a part to a MM profile, the buffer profile disappears and two fields appear in the Buffer Sizing section: the Top of Max and Top of Min.

Note that the Top of Min = Red Zone value, but the Top of Max = Red Zone + Green Zone. You are not entering the individual Green and Red Zone values. You are entering in the top of the MM buffer and the Top of the Red Zone in the Buffer.

To properly enter in the Min and Max values, you should first add together the Green and Red Zones you calculated earlier. This quantity will be your "Top of Max". Then enter the Red Zone quantity in the "Top of Min".

Once you have successfully entered these values, you will want to prevent anyone from overriding this assignment with the Smart Buffer Profiler. Make sure you immediately "Lock" the Min Max profile by clicking the "Lock Profile Assignment" setting to "Yes". This will ensure that no one accidentally removes it in the next buffer profile review.

Then select "Save" to save your work and officially assign the MM profile to your part.

Changing to a Replenished Override Buffer Type

A Replenished Override Buffer profile establishes a static three-zoned buffer for a part. It is primarily used for parts that have defined limitations in the planning environment, such as space constraints, cash constraints, etc. In these situations, a dynamic buffer could grow or shrink outside of the specific requirements for that item. A static buffer can provide more control for these situations.

You will be able to use the same dropdown menu in the Part record to convert the part to an RO buffer type. Instead of selecting a new buffer, scroll to the top of the dropdown and select the "RO" option. The buffer will disappear, leaving you to enter the values of the green, yellow, and red zones.

Green Zone Guidelines for RO

The RO buffer type will still follow the same guidelines as a regular buffer in that it will issue a recommended reorder quantity when the Net Flow enters the Yellow Zone. This means that, unless there are space constraints or cash constraints around ordering, the Green Zone should follow the same logic as a regular buffer's green zone. The Green Zone for an RO buffer should often either be the MOQ or the Order Cycle Day x EDU. Also like a normal buffer, it is recommended that you use whichever is the largest.

If there are space or cash constraints around ordering, the Green Zone should be modified to respect these constraints. For example, if there are already space constraints for the inventory of the part, the size of the Green Zone should also be limited to ensure that the planners do not order too much to receive and store.

Yellow Zone Guidelines for RO

The Yellow Zone's role is to be the primary coverage for your part. It does not have any influence on the size of the average inventory that you will hold for the part. Because of this, it should almost always be calculated the same way in an RO buffer as it is in a normal Replenished Buffer. This calculation is EDU x LT. Because the EDU is static, the EDU should be calculated across - at least - the largest ADU and/or FDU horizons.

Red Zone Guidelines for RO

Like in the MM buffer, the Red Zone of an RO buffer should be treated a little different than the Red Zone of a typical buffer.

The Red Zone can also be thought of as the average minimum of target inventory that you would hold on a part. It's normal to see inventory levels below the Top of Red, but on average, your Target Inventory should regularly be a little above the Red Zone.

With an RO buffer, the goal is to respect potential limitations on inventory levels while also maintaining enough coverage to protect that part over time. For example, if there are space constraints, the Red Zone should generally be sized to the level of that constraint.

The above RO guidelines are just that: guidelines. There are always exceptions. Although these can assist in your initial RO buffer calculations, if you are unsure if you have the right selections for your RO buffers - or if you should even be using an RO buffer - reach out to your implementation consultant or [email protected].

Entering the Zone Values

Once you have determined the zone values that you wish to use, it is time to enter the right values into the RO settings in the Part record. When you set a part to a RO profile, the buffer profile disappears and a "Top of Zone" field appears for each of the three zones in the buffer.

Note that the new fields for RO are "Top of Zone" fields. This means that you are not entering the quantity of the field itself, but instead adding together the value of that zone and the zone(s) beneath it to achieve the correct field values.

To properly enter in the Zone values, you should enter in the values from bottom to top. This will assist you in adding together the correct zone values and typing in the correct sizing for each "Top of Zone" field. Use the table below to determine which fields to add together to achieve the correct Top of Zone value.

Top of Zone Field	Math
Top of Red Zone	= Red Zone Quantity
Top of Yellow Zone	= Red Zone Quantity + Yellow Zone Quantity
Top of Green Zone	= Red Zone Quantity + Yellow Zone Quantity + Green Zone Quantity

Once you have successfully entered these values, you will want to prevent anyone from overriding this assignment with the Smart Buffer Profiler. Make sure you immediately "Lock" the RO profile by clicking the "Lock Profile Assignment" setting to "Yes". This will ensure that no one accidentally removes it in the next buffer profile review.

Then select "Save" to save your work and officially assign the RO profile to your part.