Choose candidates

In the Candidates page you can choose and group the crudes, feedstocks or products you want to test in your analytic.

• In the Crude Evaluation analytic, the list shows the crudes that can be blended into the Base Blend. This list is taken from the Crudes tab of the Purchases table of the analytic parent case. Each crude marked as Active is blended in turn into the base blend, to understand its effect on the plant operations.

• In the Feedstock Evaluation analytic, the list shows the feedstocks that can be blended into the Base Blend. This list is taken from the Imports tab of the Purchases page of the analytic parent case. Each feedstock marked as Active is blended in turn into the base blend, to understand its effect on the plant operations.

• In the Product Evaluation analytic, the list shows the products that are manufactured. This list is taken from the Sales page of the analytic parent case. For each product marked as Active, a case is generated in which an extra tranche of product is added with the price and constraints defined on the Candidates page.

Groups

In the Group column, you can assign candidates either to group A or group B.

• In the Crude Evaluation and Feedstock Evaluation analytics, each candidate in group A is added separately to the base blend in order to generate a case. Each candidate in group B is added separately to each case generated from group A, and is also added by itself to the base blend. The aim is to help you understand if there are any synergies between the group B candidates and the other candidates in group A.

• In the Product Evaluation analytic, each candidate in group A is added separately as a tranche in order to generate a case. Each candidate in group B is added separately to each case generated from group A, and is also added by itself to the product slate.

  

The following image of the Case Stack page shows that the Nemba crude, in group B, is included together with Lower Zakum and Mars (crudes in group A) in the third and fourth rows, but also included by itself in the fifth row. Something analogous happens with feedstocks and products.

Remove crudes, feedstocks or products

In the Crude Evaluation and Product Evaluation analytics, clear a check box in the Active column of the Candidates page if you want the corresponding crude or feedstock to be excluded from the base blend. An additional case is run with that particular crude or feedstock marked as inactive, and therefore unavailable for purchase. Note that, if the crude or feedstock is marked as active in the Base Blend page, a case including that crude or feedstock will still be run.

In the Product Evaluation analytic, you can remove products from production by following these steps:

1. Ensure the product is Active on the Product Slate page.

2. On the Candidates page, clear the Product Slate check box for the product. This ensures that the original product production is deactivated in the analysis.

3. Ensure the product is Active on the Candidates page. This adds another tranche of candidate for the product.

4. Set the amount of the Fixed constraint to zero. This ensures the new tranche of candidate is not produced. However, the material is still present returning a marginal value on the sale if appropriate.