Retrenchment
Nobody did anything wrong. That is what makes it hard.
An operational-requirements dismissal is the only kind where fault plays no part, which means the whole of the fairness enquiry is about the process. Employers lose these on procedure almost exclusively, and employees who understand that are in a much stronger position.

Five steps
What section 189 actually requires.
Identical for both sides, so it is set out once. What differs is what each of you should do at each step.
A written notice inviting consultation
It must set out the reasons contemplated, the alternatives considered and why they were rejected, the number of employees likely to be affected, the proposed selection method, the timing, severance proposed, and assistance offered. A notice missing half of that starts the process badly and it is the first document the CCMA will read.
Consultation, which means a joint problem-solving exercise
Not an announcement with a comment period. The employer must allow the other party to make representations and must respond to them — in writing, if the representations were in writing — and must consider them properly before deciding.
Selection on agreed or fair and objective criteria
If the parties agree criteria, those apply. If not, the criteria must be fair and objective, and LIFO is the usual default. "Attitude" and "not a team player" are neither fair nor objective and they do not survive scrutiny.
Severance pay
At least one week’s remuneration per completed year of continuous service, unless a bargaining council agreement or contract says more. An employee who unreasonably refuses a reasonable offer of alternative employment loses the entitlement.
Notice, and then the dispute
A retrenchment dispute about procedure or substance goes to the Labour Court, or to the CCMA where a single employee is affected or the employee elects arbitration in certain cases. Which route applies is a live question and getting it wrong costs months.
Four things, twice each
Where retrenchments actually fail.
Section 189A changes almost everything, and it is easy to miss.
If you are the employer
If you are the employee
Disclosure is not optional.
If you are the employer
If you are the employee
Alternatives have to be genuinely considered.
If you are the employer
If you are the employee
A retrenchment used to remove one person is not a retrenchment.
If you are the employer
If you are the employee
The same advice to both of you
Put it in writing, and answer in writing.
A retrenchment is judged almost entirely on the paper trail. An employer who responds to written representations in writing has built the defence as it goes; an employee who makes them in writing has built the case. Meetings with no minutes help whichever of you is willing to remember them differently, and neither of you should want to be that party.

Send us the section 189 notice.
It is one document and it tells us most of what either side needs to know about how this is going to go.