Working with Alternate Sets

Some projects might contain a choice of two or more ways to accomplish the work or a piece of the work. The different ways to accomplish the work might require different work items or groups of work items. For example, a paving project might allow a choice between asphalt and concrete, or bridge construction might involve a choice between two designs, each requiring a different set of supplies.

For this reason, two or more items or groups of items can be identified as alternate means to accomplish a given project need. The need is indicated by defining an alternate set. The system offers two types of alternate sets: Item Alternate Sets and Category Alternate Sets.

Regardless of the type of alternate being considered, bidders must bid on at least one of the alternatives or they would not have a complete bid. Some agencies require that bidders submit a bid for each of the alternatives in order to have a complete bid.

Item Alternate Sets

Item Alternate Sets include individual items that can serve as alternates for each other. The entire set of options is defined as the Item Alternate Set, and each unique option is designated as a member of that set.

For example, the need to provide gravel can be addressed by defining an Item Alternate Set named 'Gravel' that includes multiple types of gravel, each of which serves as an alternative the bidder can choose to provide. In this example, #2 stone and #4 stone might both be allowable types of gravel. Both the #2 stone and #4 stone are members of the set. Each type of gravel is an alternative to the other type.

Caution for Bids users: While alternate items can reside in separate categories and sections, it is recommended that they be in the same category and section to avoid potential issues when running the GEN process.

Category Alternate Sets

Category Alternate Sets follow the same concept, but consist of multiple items grouped together to meet a particular project requirement in a given way. The requirement is defined as a Category Alternate Set, and each member of that set is a category containing the group of items required.

For example, a Category Alternate Set named 'Paving' might contain two categories, one consisting of the items needed to provide asphalt paving, and the other consisting of items needed to provide concrete paving. The 'Asphalt' category would contain the items needed for asphalt paving, such as aggregate and seal coat. The 'Concrete' category would contain the items needed for concrete paving, such as concrete and joint sealant. Each type of paving is an alternative to the other type.

Category Alternate Sets might also contain one or more alternate items. The interrelationships between item and category alternates can make designing such a project very complex. For a detailed explanation of the rules by which the system progresses project categories to proposal sections and how alternate sets impact this process, see Special Information About Category Alternates.

Note: All members of an item alternate set must be assigned to the same category if that category has been defined as an alternate.

The following topics offer examples to help you understand how to successfully set up alternate categories and items in one or multiple projects. There are four scenarios of increasing complexity, with one example demonstrating a common error and how to correct it:

Example 1 - A Simple Scenario
(a project with alternate categories and items)
Example 2 - A More Complex Scenario
(two projects with alternate categories and alternate items, but all set and member values are unique)
Example 3 - A Complex Scenario
(two projects with alternate categories and alternate items using the same category alternate set and member names)
Example 4 - A Complex Scenario containing an Error
(two projects with alternate categories and alternate items using the same category and item alternate set and member names incorrectly applied)
Example 5 - Using Category Alternates to Create Project-Level Alternates (two projects with multiple alternate sections with the same set/member and different section groups)