A purchase order is a document sent from a buyer to a seller, with a request to order a product. The purchase order often has its number, description and quantity of the goods, unit prices and total price, name of issuer, time of delivery, standard terms and conditions, etc. It is effectively an offer to supplier. The purchase order will become a formal contract if supplier accepted it by written notice or by performance (such as deliver the goods to the buyer's premise).
Reference: CIPS study guide page 33
LO 1, AC 1.2

Liquidated damages are presented in certain legal contracts as an estimate of otherwise intangible or hard-to-define losses to one of the parties. It is a provision that allows for the payment of a specified sum should one of the parties be in breach of contract.
Liquidated damages are meant as a fair representation of losses in situations where actual damages are difficult to ascertain. In general, liquidated damages are meant to be fair, rather than punitive.
Limitations of Liquidated Damages
It is possible that a liquidated damages clause might not be enforced by the courts. This can occur if the monetary amount of liquidated damages cited in the clause is extraordinarily disproportional to the scope of what was affected by the breached contract.
Such limitations prevent a plaintiff from attempting to claim an unsubstantiated exorbitant amount from a defendant. For instance, a plaintiff might not be able to claim liquidated damages that amount to multiples of its gross revenue if the breach only affected a specific portion of its operations. The concept of liquidated damages is framed around compensation related to some harm and injury to the party rather than a fine imposed on the defendant.
The courts typically require that the parties involved make the most reasonable assessment possible for the liquidated damages clause at the time the contract is signed. This can provide a sense of understanding and reassurance of what is at stake if that aspect of the contract is breached. A liquidated damages clause can also give the parties involved a basis to negotiate from for an out-of-court settlement.
Reference:
- Liquidated Damages
- CIPS study guide page 158-159
LO 3, AC 3.2

There are number of reasons why the purchaser will want to control the supplier's subcontracting:
- Supply chain transparency: Normally the purchaser has invested a lot of effort into selecting the right contractor. However, the main contractor's selection of subcontractor might not be in such careful manner, which may result in poor performance. Purchaser must know who subcontractors are. Controlling the subcontracting process can help the purchaser control the outcome.
- Contract terms: the purchaser's requirements must be reflected in the subcontracts. The subcontracting clauses may require the main contractor to do this.
- Liability: the main contractor may subcontract the whole or a part of its liabilities. Subcontracting clause may bind the contractor to be liable with the work, it cannot just blame the subcontractor for any faults.
Reference:
LO 3, AC 3.2

In the contract term, the buyer agrees to pay the contractor the cost of doing project plus a profit. This is an example of cost-plus pricing arrangement.
On the other hand, "Fixed-pricing arrangement" often refers to lump-sum contract or supply/service contract with fixed price. "Incentive pricing arrangement" and "Gain-share/pain-share arrangement" have the same meaning. In this type of arrangement, both supplier and buyer agree on a target (it can be cost, or lead time, or quality, etc). Once the supplier reaches that target, it will be rewarded with a portion of the gain that the buyer gets, and will pay the price if it fails.
Reference: CIPS study guide page 176-178
LO 3, AC 3.3

In the contract term, the buyer agrees to pay the contractor the cost of doing project plus a profit. This is an example of cost-plus pricing arrangement.
On the other hand, "Fixed-pricing arrangement" often refers to lump-sum contract or supply/service contract with fixed price. "Incentive pricing arrangement" and "Gain-share/pain-share arrangement" have the same meaning. In this type of arrangement, both supplier and buyer agree on a target (it can be cost, or lead time, or quality, etc). Once the supplier reaches that target, it will be rewarded with a portion of the gain that the buyer gets, and will pay the price if it fails.
Reference:
LO 3, AC 3.3