Systems and user interface

Two systems are developed to implement the mechanisms. Imaras, as a technical-level meta-system, supports different auction settings at the implementation level including: information display (limit- sets only, bidder’s own bids, winning bids and all bidders’ bids), continuous bidding or round-based bidding, fixed or flexible round duration and auction length (i.e. hard deadline, extendable). Also, a set of relevant features can be used and configured to provide analytical support for bidding, (e.g. bid construction, validation and generation using the bidder’s preferences and the limit-sets), visualization support for reviewing the bidding history and predicting the trend (i.e. bids distributed

over a time span).

Imbins supports negotiations in which one buyer simultaneously negotiates with several suppliers by exchanging offers and/or messages. It may also vary at the system implementation level with different features, including: analytical support (e.g. offer construction, comparison and generation), communication support (e.g. messaging) and visualization support (e.g. offer-history graph).

In order to implement and compare mechanisms, similar system features and user interfaces are developed in these systems. Figure 4-6 and Figure 4-7 show the main user interface of each system. More relevant system screenshots are provided in Appendix A for Imaras and Appendix B for Imbins to demonstrate the system user interface, key features and functionalities, and their use in a business procurement scenario. Video demonstrations of the two systems are also available online (see the demo at Imaras 2011; Imbins 2011).

The Imaras screen in Figure 4-6 is the bidding screen of a round-based auction in which the bidder can see her own bids as well as the winning bids. The Imbins screen in Figure 4-7 shows the message and offer submission screen in which the negotiator can see her own offers and messages as well as those of the counterpart.

Both screens have four main components. The clock (A) shows the time from the beginning of the auction and the time left to the deadline. The systems’ navigation bars are located on the right- hand side (B) where links to active pages are listed. For auctions, the round number and clock are also given. The clock is reset at the beginning of every round.

In both bidding and offer screens, the most recent bids or offers made by the supplier (who sees this screen) and by the buyer are shown (C). In auctions, only winning bids and bids made by the bidder who sees this screen are shown. In negotiations, only offers made by the buyer to all suppliers or to the supplier who sees the screen are shown.

Figure 4-6. System screen of bid construction and submission in Imaras

The most recent bids and offers are shown in both tabular and graphical forms. (The complete list of bids and offers can be seen on separate pages: Auction history and Negotiation history pages are accessible from the menu in (B). One difference between the auction and negotiation pages is that in the auction page, the round is given as well as the bidder who submitted the winning bid. In the negotiation page, messages sent by a counterpart can be accessed (they are expandable). Bids and offers are constructed and submitted in (D).

The two main differences between auctions and negotiations are in the limit-sets for the former and messaging facility for the latter. In the Imaras screen (left-hand side of D), three limit-sets are provided. The bidder can select one set (table row) and then select admissible attribute values for the given set (Figure A-2 in Appendix A). Then in the next table (bid submission) the selected values will appear thus composing a complete bid to submit. In the Imbins screen (D), there is a message box that allows the user to write and send a message to the counterpart.

Moreover, to assist the cognitive effort in decision making and communication in a one-to-many situation, the two systems provide additional support. In Imaras, aside from the list of bids in a table, the bidding process is also graphically visualized. Based on the bidder’s preferences, the graph depicts the bids during the process (Figure A-5a in Appendix A). This visualization provides a holistic view of the auction process, allowing the comparison of the bids and the prediction of the bidding process. The system can also generate a similar graph from the buyer’s perspective, which depicts all bidders’ bids as compared to the value of limits in each round (Figure A-5b in Appendix A). As the selection of winning bids and calculation of limit sets are automatically completed by the system, this may be used to monitor the real-time bidding status and to review the bidding process.

In Imbins, as the offer comparison and construction are performed by human buyers, a negotiation update screen was designed in which the most recent offers and/or messages from each supplier are listed together (Figure B-1 in Appendix B). This screen dynamically updates the

negotiation status and provides real-time information to the buyer, who can evaluate and reply to the offers, reply to the messages, or accept a preferable offer to reach an agreement. Similar to Imaras, the offers exchanged during the process are also depicted on a graph (Figure B-2 in Appendix B). From the suppliers’ perspective, the negotiation process is visualized by showing their own offers and the buyer’s offers based on the suppliers’ preferences over time. From the buyer’s perspective, the graph shows the buyer’s offers and all suppliers’ offers based on the buyer’s preferences. This visualization provides a holistic view of the negotiation process and supports offer comparison and prediction.