TWO STRATEGIES
Compare two routes to the same finish line while keeping progress and cost separate
This calculator evaluates two declared strategies from one starting point and one horizon. Each route has its own output rate, adherence assumption, one-off contribution, and weekly cost. It reports goal and budget status separately because a cheaper route is not automatically more useful and a faster route is not automatically affordable.
| Strategy layer | Weeks | Effective rate | Total | Unit |
|---|
Detailed calculation process
Formula, declared symbols, substitutions, intermediate results, and reconciliation
QA = Q0 + W·aA·rA + xA; CA = W·cA (and likewise for B)
For each strategy, weekly units are multiplied by adherence and horizon, then one-off units are added. Weekly cost is totaled independently; no composite score is used.
| Symbol | Meaning | Unit / default |
|---|---|---|
| Q, Q0 | goal and common accepted baseline | units; Q0=40 |
| W, rA, rB | weeks and scenario weekly output rates | 16 weeks; 18 and 15 units/week |
| aA, aB | adherence fractions after percentage conversion | 0.80 and 0.95 |
| x, c | non-repeating output and weekly cost | A:15/$35; B:5/$20 |
- Convert adherence percentages: 80%=0.80 and 95%=0.95.
- A recurring output=16×18×0.80=230.4 units; A total=40+230.4+15=285.4.
- B recurring output=16×15×0.95=228 units; B total=40+228+5=273.
- A cost=16×$35=$560; B cost=16×$20=$320.
- Compare each total with the entered goal using the same sign convention.
- Final reconciliation: A exceeds B by 12.4 units and costs $240 more; each total equals baseline plus recurring plus one-off output.
How to compare
- Freeze one goal and horizon.
- Estimate each route’s observed weekly output.
- Reduce output by route-specific adherence.
- Enter genuine one-off progress once.
- Record recurring cash cost.
- Inspect goal and budget statuses separately.
Five scenario foundations
Baseline
Current accepted progress shared by both routes.
Adherence
Fraction of planned output expected to occur.
One-off unit
Non-repeating progress.
Budget cap
Maximum total spend under review.
Scenario
Coherent set of assumptions, not a prediction.
Deep dives
Correlation
Adherence and output may move together; multiplying fixed values can understate that dependency.
Quality equivalence
Units must have the same acceptance standard under both routes.
Dominance
A route dominates only if it is no worse on every declared outcome, not because one number is larger.
Evidence
Base output and adherence on route-specific logs from comparable weeks. Preserve invoices or quotes for cost. A goal-met flag means arithmetic reach under assumptions; it does not certify completion quality.
Limits
- No uncertainty distribution.
- No time value of money.
- Constant weekly rate.
- No quality or preference score.
- No causal claim about strategy choice.
Glossary
- Baseline
- Shared starting amount.
- Effective rate
- Weekly units after adherence.
- Goal gap
- Target minus projected units.
- Dominance
- No worse on all compared outcomes.
- Sensitivity
- Output change after an assumption changes.
- Scenario boundary
- Condition excluded from the model.
Cases
Language study: the intensive route costs more yet still misses the unit target after realistic attendance.
Renovation prep: both routes miss, but the low-cost route preserves budget for a specialist dependency.
Important note
Do not choose between material commitments using this comparison alone; inspect quality, reversibility, safety, and contractual terms.
Result interpretation
Compare trade-offs, not a manufactured winner
Scenario A produces 12.4 more units in the default record but costs $240 more. The output does not say whether that exchange is worthwhile. Check whether both scenarios clear the required goal, then compare the extra cost with the value, reversibility, workload distribution, and reliability of the assumptions.
Decision and sensitivity
Adherence can reverse an apparently faster plan
Each five-point adherence change moves A by 16×18×0.05=14.4 units and B by 12 units. That is similar to the entire default output difference, so an unverified adherence estimate can reverse the ranking. Preserve a low, base, and high adherence case instead of treating one percentage as precise.
Questions
Why not make one winning score?
A blended score hides whether progress or money drove the ranking. Keep projected units, goal gap, and cost visible so partners can apply their own priorities.
Is adherence a probability?
Here it is a planning fraction applied to weekly output, not a statistical probability. It should come from comparable follow-through records, not confidence alone.
Can one-off work repeat?
No. Put recurring output in weekly units. Repeating the same one-off credit in later reviews would overstate cumulative progress.
What if both miss the goal?
The comparison still shows which gap and cost profile each creates. Consider a third scenario that changes scope or horizon rather than choosing the smaller miss automatically.
Does lower cost mean better?
Not necessarily; quality, risk, and preferences remain outside the arithmetic. A cheaper scenario may transfer more work or produce less durable output.
Can this forecast actual completion?
No. It is a declared-assumption scenario, not a validated forecast. Reconcile each review period against accepted output and actual spending.
Why use the same starting progress for both scenarios?
A common baseline isolates the effect of future assumptions. If the scenarios truly start from different accepted work, document separate baselines and avoid a direct ranking.
How should adherence above 100% be handled?
Do not enter it as adherence. Increase the evidenced weekly rate or record a one-off contribution so each assumption retains a clear meaning.
Can weekly costs include shared fixed costs?
Yes, if both scenarios receive the same relevant allocation rule. Record the basis so a fixed cost is not counted twice or assigned only to the less favored option.
When should a scenario be retired?
Retire it when its assumptions are no longer available, lawful, affordable, or acceptable. Preserve the old record so the decision history remains auditable.