2.4 Market testing means the re-tendering by the PPP contractor of the relevant soft service so that the public sector can test the value for money of an existing service against the wider market of suppliers. Any increase or decrease in the cost of such service following market testing which results in the replacement of a sub-contractor should be reflected by an adjustment in the price charged to the Authority. The Project Agreement should specify the relevant percentage movement in the contractor's costs which will trigger a price adjustment to the unitary charge. Application of this process in a PPP, and subject to Project Agreement provisions is likely if the public sector (and perhaps also the PPP contractor and funders) has reason to be dissatisfied with the existing service provider, either in performance or price. This dissatisfaction may have prevailed through a benchmarking exercise and failure to agree the outcome of benchmarking would normally lead to a market test exercise. Market testing involves evaluation and comparison of tenders and is therefore likely to result in a negotiation exercise. This Briefing Note and related principles will be applicable to a negotiation including negotiating changes to the wider FM contracts.