Workstream Settings and Configuration
Every workstream has a Settings tab where you configure the channel, operating hours, cost model, and staffing assumptions. You can access it at any time — changes take effect immediately and recalculate all dependent tabs.
Channel Selection
The channel determines which staffing formula Turnella uses. This is the most important setting in a workstream.
| Channel | Formula | When to use |
|---|---|---|
| Inbound voice | Erlang C | Telephone calls where callers queue and wait for an agent |
| Live chat | Concurrency model | Real-time text chat where agents handle multiple sessions at once |
| Backlog throughput model | Asynchronous email, tickets, or back-office cases with an SLA deadline | |
| Back-office | Backlog throughput model | Any deferred task work without a real-time queue |
Do not mix channel types in one workstream. If a team handles both voice and email, create two separate workstreams — one for each channel.
Operating Calendar
The operating calendar tells Turnella when your team works. This affects:
- Which intervals appear in the forecast and requirements charts (non-operating intervals are excluded)
- Which intervals are included in coverage calculations
- Which schedule shifts fall within or outside operating hours
Setting operating days and hours
Tick the days your team operates and set the start and end time for each day. You can have different hours on different days — for example, 08:00–20:00 Monday to Friday and 09:00–17:00 Saturday.
Bank holidays and closures
For planned closures, add a closure date in the calendar. Turnella excludes that date from coverage calculations and the forecast treats it as a zero-volume day (or applies an event multiplier if you have configured one).
Staffing Assumptions
The assumptions panel controls all the inputs used in the staffing formula. All values can be changed at any time — the requirements tab recalculates instantly.
Voice assumptions
| Assumption | What it controls | Typical range |
|---|---|---|
| AHT (Average Handle Time) | Mean seconds per call including wrap-up | 120–480 seconds |
| Service level target | % of calls answered within the target time | 70–90% |
| Target answer time | The "within X seconds" threshold in your SL target | 10–30 seconds |
| Max occupancy | Ceiling on agent busyness; extra agents added to stay below this | 75–90% |
| Shrinkage | % of scheduled time agents are not available for contacts | 20–40% |
Chat assumptions
| Assumption | Typical range |
|---|---|
| AHT — Chat (seconds) | 300–900 seconds |
| Max concurrent sessions per agent | 2–4 |
| Active time ratio | 0.60–0.75 |
| First-response SL target | 80–95% |
| Shrinkage | 20–30% |
Email/back-office assumptions
| Assumption | Notes |
|---|---|
| AHT per item (seconds) | Time to fully process one email or case |
| Efficiency | % of paid time on productive work (60–80% typical) |
| Available hours per FTE per day | Paid hours per agent per day |
| Backlog reduction target | % of existing backlog to clear in the planning window |
Cost Model
Configure your cost model in Settings → Cost Model to enable the Cost tab:
- Default hourly rate — base wage per agent per hour (before employer costs)
- On-cost uplift — employer costs as a % of wage (NI, pension, holiday pay). UK typical: 22–28%.
- OT premium — overtime pay as % of base rate (e.g., 150 = time-and-a-half)
- Night premium — % uplift for shifts starting at or after 20:00
- Weekend premium — % uplift for Saturday and Sunday shifts
- Weekly budget — target weekly spend; Cost tab shows RAG status against this
Role rates
If your team has multiple pay grades, add a role for each grade with its own hourly rate. Assign roles to shift templates in the Schedule tab and the Cost tab will use the correct rate per shift.
Attrition and Hiring
Configure an annual attrition rate (% of the team who leave each year) to enable the Insights tab's hiring alerts and attrition runway chart. UK contact centre industry average attrition is 25–40% per year.
Also configure:
- Ramp time — weeks until a new hire is fully productive (typically 4–8 weeks)
- Contractor rate — hourly day rate for temporary agency workers, used in the overtime/temp/hire comparison
Deflection Config
If you are implementing or planning self-service deflection (IVR, chatbot, web self-service), configure the expected deflection rates here:
- Start deflection % — the volume reduction in month one
- Monthly increase — how much deflection grows each month
Turnella applies this as a downward multiplier on the forecast and shows a separate deflection line in the Forecast tab chart. This is useful for modelling how self-service investment will change your future headcount requirement.