Using the weighted-point approach, the scores for each category are weighted and totaled for each supplier as follows:
* Supplier A: (40% * 3) + (20% * 5) + (20% * 5) + (20% * 4) = 1.2 + 1.0 + 1.0 + 0.8 = 4.0
* Supplier B: (40% * 4) + (20% * 3) + (20% * 3) + (20% * 4) = 1.6 + 0.6 + 0.6 + 0.8 = 3.6
* Supplier C: (40% * 5) + (20% * 4) + (20% * 3) + (20% * 4) = 2.0 + 0.8 + 0.6 + 0.8 = 4.2
* Supplier D: (40% * 4) + (20% * 4) + (20% * 5) + (20% * 4) = 1.6 + 0.8 + 1.0 + 0.8 = 4.2 Since Suppliers C and D both score 4.2, the tie is broken using factors related to employee resources. Supplier D scores higher in these categories, making Supplier D the best performer. References: Supplier performance evaluation methods, weighted-point evaluation model, tie-breaking criteria in procurement.

The primary risk XYZ Company faces when issuing a new RFP, after previously not selecting any supplier, is the potential reluctance of suppliers to participate again:
* Suppliers may decline to respond because XYZ has issued RFPs twice in the past without selecting anyone: This is a significant risk as suppliers may perceive it as a waste of resources and time, reducing the pool of potential responses.
* Procuring the app from a third party when it was not purchased from a supplier during the previous years could result in the firm exceeding its budget: Budget management is a concern but not the greatest risk.
* XYZ may be forced to accept a proposal that does not meet its business requirements: This can be mitigated by clearly defining requirements.
* XYZ's timetable might place an unreasonable burden on the ability of suppliers to prepare and submit responses: While timeline concerns are valid, suppliers declining to respond due to past experiences is a more immediate risk.
Therefore, the greatest risk is that suppliers may decline to respond because XYZ has issued RFPs twice in the past without selecting anyone.
References:
* Procurement strategy literature on supplier engagement.
* Best practices in managing RFP processes.

When dealing with a complex system implementation in stages, it is critical to begin the project promptly to maintain the schedule. However, if later milestones and deliverables are not yet defined, a flexible approach is necessary. Creating an initial Statement of Work (SOW) allows the project to start with the first phase, and provisions for negotiating subsequent SOWs as the project progresses ensure that the remaining stages can be defined in detail later. This approach balances the need for a timely start with the flexibility to adapt as more information becomes available.References:
* Project Management Institute (PMI). A Guide to the Project Management Body of Knowledge
* (PMBOK Guide).
* CIPS (Chartered Institute of Procurement & Supply) guidelines on SOW management.