Specifications

Manufactured products have to meet sets of specifications in order to be saleable within a particular market, and each product usually has many different applied specifications, which may be legal requirements or agreed upon with the purchasers. For essentially the same product there may also be slightly different sets of specifications depending upon the final market.

These sets of requirements are managed in AVEVA Unified Supply Chain using grades. A specification criterion is a property value, typically a minimum or maximum that a product must meet.

Example: The cold filter plugging point (CFPP) must be less than 0° C. This criterion is associated with a material specification, which is a set of criteria defined for a traded material. For example, the CFPP value may be associated with Ultra Low Sulfur Diesel (ULSD) 15ppm (that is, with less than 15ppm sulfur), and ULSD 15ppm is a traded material of the Diesel material type.

Grades

In AVEVA Unified Supply Chain, products are often manufactured by blending different outputs by process units in order to meet a set of specifications. The products that AVEVA Unified Supply Chain can manufacture are traded materials. Often a single product type may be produced in several different grades. These different grades represent the same type of product, but have a different associated set of specifications and may also have a different set of intermediate products that can be pooled in their manufacture. The exact blending pool depends on a plant configuration, and the set of specifications the product grades are blended to are usually defined by local regulations.

Example: Gasoline may be sold as 87 MON or 90 MON. If a refinery produces alkylate, it may sometimes be pooled in 90 MON gasoline but not the 87 MON gasoline.

The product specifications associated with each product grade are defined on the Grades page. Each final product grade is associated with one or more Specifications. These specifications are composed of a collection of property Criteria which define the limits for the specified properties. These limits can be either a minimum or maximum property value; it is also possible to specify acceptable ranges for a criteria by entering both a minimum and maximum.

Example: 87 MON gasoline is defined by a specification which includes criteria limiting density, benzene content, motor octane number and so on. The specification defines a minimum motor octane rating, and usually a range of acceptable density values, defined by a minimum and maximum density value.

Add a grade

Tip: Before adding a new grade and its associated specifications, ensure that the traded material with which the set of specifications will be associated is present in the traded materials list. See Materials Hierarchy for more information on how material types, traded materials and material specifications are related.
Different seasonal specifications often have different traded materials. For example, if you have a summer and winter ULSD, there are two traded materials, ULSD Summer and ULSD Winter, each of which has one matching grade.

To add a new grade, click the Add Grade button in the Grades group of the Home ribbon tab, or right-click and choose Add Grades from the context menu. This adds a new grade to the table immediately, where you can edit it using the drop-down menus and editable text fields.

Delete a grade

To delete a grade, either:

• Select the grade to be removed and click Delete Grade on the Grades group of the Home ribbon tab.

• Select the grade to be removed and select Remove Grade from the context menu.

Undo pending changes

You can undo changes you have made on the Grades page, but have yet to commit to the server. You will know a change has been made because:

• The database icon on the far left will have a red tick over it when a change has been made in that row. It will remain there until you have committed these changes.

• The cell that has changed will turn into bold font, until it is committed.

• If a value was set, and then cleared or deleted, <Value Cleared> is displayed in its place.

To undo your changes, right click on the cell in question, and select the Undo Change option. This will revert the cell to its original value.

Specifications

The Specifications page shows the globally available products and their associated specifications. These materials can be added to any supply chain model, and if these materials are then updated the supply chain models can be automatically updated with the new data. Models in a private share may have their own independent specifications, which are not part of global reference data. Private specifications will automatically be moved to a public share if the private model is published for general use.

When a sale is added to a supply chain model, the specification associated with the grade is used to define the limits of sold material. These limits will appear in the supply chain model within the Blending > Specification grid.

By default, the Specifications grid shows grades as columns and properties as rows. For each grade, a Min and Max columns show any constraints on property values, and whether these constraints are active. A constraint is active if the check box next to the constraint value is selected.

You can filter the properties and grades shown in the tab by typing in the Properties and Grades fields at the top of the table.

Report on property values

It is possible to report on property specifications rather than ensuring they are met during blend optimization. To report on a property specification for a grade, all the resultant components of that final blended grade must possess a value for the particular property.

To set a property for reporting, select the required grade and property to report on, right-click and from the context menu select Report on this Property.

If one of the blend components does not have a particular property value, the value for this property will not be reported. However it will not affect the blending of the grade.

Example: If a fuel oil was to be manufactured by blending vacuum gas oil and vacuum residue, and had an ash value set as a report on property, then as long as the vacuum gas oil and vacuum residue both had ash contents in the model, it would be possible to report the final ash value for the product. If only the vacuum residue had an ash value, it would not be possible to report the final product ash value, but the product would still be manufactured.
In contrast, if the product had an ash specification of a maximum percentage of ash and only the vacuum residue had an available ash content value, the optimization would fail as it would not be possible to calculate the ash content of the final product and use this during optimization.

Add properties

To add a new property specification:

1. Click the Add Property button in the Specifications group of the Home ribbon tab when the Specifications tab is open.

2. In the Add Property dialog select the name of the property for which the criteria will be added using the Property menu. You can type the property name in the text box to filter the list.

3. Select the unit of measure for the property in the UoM menu.

4. Click OK to confirm your choices.

Remove properties

To remove a property specification, either:

• Select the property to be removed and click Delete Property in the Specifications group of the Home ribbon tab.

• Select the property to be removed and choose Delete Property from the context menu.

Specification offsets

Specification limits are used as hard bounds during optimization. Products must meet these specification values to be saleable and provide a feasible solution. In reality there is a certain degree of measurement error when determining the true property value, which may result, among other things, from reproducibility errors in measurement or problems in blending to an exact recipe.

In order to account for these, it is common to include an offset alongside the actual specification value. This is a safety region which is added to the actual specification value to allow for problems during the actual manufacture of the final product. Margins for minimum property values are positive, so that the property value is greater than the absolute limit, and margins for maximum property values are negative.

Example: The aromatics specification of gasoline may be 35% by volume. However, due to the limitation of the test and blending, you may only be able to measure this within a ±1% degree of error. Therefore this 1% margin can be applied to the maximum as a negative offset for safety, so that the final product blend from optimization must have a maximum of 34% (35 - 1).

RFG specifications

Along with other property specifications, AVEVA Unified Supply Chain can also blend materials to reformulated gasoline specifications. As reformulate gasoline is defined using complex formulae, the required specifications are added using a special dialog.

To add an RFG specification to a product:

5. Select the required product to add the specification to.

6. Right-click the product and from the context-menu select RFG Specification > Add RFG Specification....

7. In the Add RFG Type dialog select the appropriate Area, Season, Phase, Type, Equation and Country.

8. The required properties to calculate the RFG specification is added to the property grid. All these properties must be available on all materials present in the gasoline blending pool.

Optionally you can enable specifications for RFGBOB gasoline (reformulated gasoline blendstock for oxygenate blending):

9. Select the RFGBOB check box.

10. Enter the percentage of blended ethanol in the Ethanol Dilution field.

11. Choose the feedstock used to describe the ethanol from the Ethanol Feedstock list.

To calculate the RFG specification values each blend component must carry the following properties:

• Sulphur (Total) (ppm)

• Reid Vapor Pressure (psi)

• C06A benzene by vol (%)

• Aromatics by vol (%)

• Olefins by vol (%)

• ASTM D86 @ 200F (%)

• ASTM D86 @ 300F (%)

• Oxygen content from MTBE (%)

• Oxygen content from ETBE (%)

• Oxygen content from Ethanol (%)

• Oxygen content from TAME (%)

Properties can be entered in any unit of measure from the appropriate unit of measure category. For example, Sulphur (Total) can be in ppm or %. Properties may have blend indices applied.

To edit RFG specifications:

12. Select the required grade to edit.

13. Right-click the grade and from the context menu select RFG Specification > Edit RFG Specification....

14. In the RFG Type dialog select the appropriate RFG parameters.

To remove an RFG specification:

15. Select the required grade to remove RFG specifications from.

16. Right-click the grade and from the context menu select RFG Specification > Delete RFG Specification.

CARB specifications

To define a California Air Resources Board (CARB) specification, click on the CARB Specification button in the Home ribbon tab, under the Specifications group. Alternatively, right-click on a value in your grid and select CARB specification > Add CARB specification from the context menu. Either of these methods will open a dialog where you can add your specifications:

Optionally you can enable specifications for CARBOB gasoline (California Reformulated gasoline Blendstock for Oxygenate Blending):

17. Select the CARBOB check box.

18. Enter the percentage of blended ethanol in the Ethanol Dilution field.

19. Choose the feedstock used to describe the ethanol from the Ethanol Feedstock list.

To calculate the CARB specification values, each blend component must carry the following properties:

• Olefins by vol

• Oxygen (%)

• D86 (vol) boiling point of 50%

• D86 (vol) boiling point of 90%

• Sulphur (Total)

• Benzene by vol

• Aromatics by vol

Properties can be entered in any unit of measure from the appropriate unit of measure category. For example, Sulphur (Total) can be in ppm or %. Properties may have blend indices applied.