In difficult negotiations and disputes, hardball tactics like punishment and threats often seem like the only way to win concessions. Some negotiators seem to believe that hardball tactics are the key to success in any negotiation. They resort to extreme demands and even unethical behaviour to try to get the upper hand in a negotiation.
The following are 8 typical hardball tactics:
1. Good cop / Bad cop
2. Low ball / High ball
3. Bogey
4. The Nibble
5. Chicken
6. Intimidation
7.Aggressive Behaviour
8. Snow Job
You can read the details of each tactic here.
In the contrary to hardball tactics, negotiators can adopt integrative approach to the negotiation. Some of integrative tactics are:
1. Expand the Pie
2. Bridging
3. Post Settlement -Settlement
Et cetera

Explanation
Trust may create value as following:
Text Description automatically generated with low confidence

LO 1, AC 1.4

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In contracts which have major commodity input, the price is determined by market forces with no individual supplier or buyer able to influence it significantly. Prices are much more variable even within long term contracts and seeking a fixed price would create financial risks for both the buyers and the suppliers. It is often intelligent to agree a contract price adjustment mechanism to allow for market price changes so both sides share risk.

The question asks about the point in time when Jane should make concessions with the supplier. These concessions should be traded after preliminary stages such as opening, testing and proposing are over and proposals move from being tentative and general to being more definite and specific. This stage is called bargaining phase. The bargaining phase is the 'meat' of the negotiation meeting.
LO 3, AC 3.1

Understanding where and with whom your supplier spends their money, or understanding the 'cost breakdowns' or 'price build-up' of the goods andservices you purchase from the supplier, will help you know where and when they can offer price concessions.
Cost information can be expressed with more impact through graphs that can be created using Excel and PowerPoint or other softwares. There are two commonly used models known as 'spend waterfall' and 'spend tree'. Spend waterfall shows the build-up of costs, while the spend tree shows all the spends that an organisation makes.
There is no graph known as 'spend candlesticks'. Candlestick chart is astyle of financial chart used to describe price movements of a security, derivative, or currency.
The aggregate expenditure model is a method of calculating GDP. The aggregate expenditure model focuses on the relationships between production (GDP) and planned spending: GDP = planned spending = consumption + investment + government purchases + net exports.