taskgraph_ts/tasks/implementation/cost-benefit/ev-calculation.md at 131e3e929b50de5749c864fbd04c4e5e3ffda52d

Files

glm-5.1 131e3e929b Decompose architecture into 28 atomic implementation tasks

Break the @alkdev/taskgraph architecture specs into dependency-ordered
implementation tasks across 8 component directories: setup, schema,
error, graph, analysis, cost-benefit, frontmatter, api, and review.
Each task has clear acceptance criteria referencing specific architecture
docs. Three review tasks serve as quality gates at critical junction
points (schemas-and-errors, graph-complete, complete-library). The
dependency graph is validated acyclic with 9 topological levels enabling
significant parallelism across independent work streams.

2026-04-27 08:30:05 +00:00

1.8 KiB

Raw Blame History

id, name, status, depends_on, scope, risk, impact, level

name

status

depends_on

scope

risk

impact

level

cost-benefit/ev-calculation

Implement calculateTaskEv pure function

pending

schema/numeric-methods-and-defaults

schema/result-types

narrow

low

component

implementation

Description

Implement calculateTaskEv(p, scopeCost, impactWeight, config?): EvResult in src/analysis/cost-benefit.ts. This is the pure math function — takes numeric inputs, returns EV result. No graph dependency.

Per cost-benefit.md:

EV = P_success × C_success + (1 - P_success) × C_fail

Where C_fail = scopeCost + fallbackCost + timeLost × expectedRetries.

Acceptance Criteria

calculateTaskEv(p: number, scopeCost: number, impactWeight: number, config?: EvConfig): EvResult
Returns EvResult: { ev, pSuccess, expectedRetries }
expectedRetries = (1 - p) / p when p > 0, else 0 (geometric series)
C_fail = scopeCost * impactWeight + fallbackCost + timeLost * expectedRetries (impactWeight scales the cost)
EV = p * scopeCost * impactWeight + (1-p) * C_fail
When config.retries is provided and > 0, caps expectedRetries at retries
When config.valueRate is non-zero, multiplies the final EV
Edge cases: p = 0 (guaranteed failure), p = 1 (guaranteed success), default config (all zeros)
Unit tests: known calculations from the Python research model, boundary values, config variations

References

docs/architecture/cost-benefit.md — EV formula, EvConfig parameters, EvResult
docs/architecture/api-surface.md — calculateTaskEv signature
docs/architecture/schemas.md — EvConfig, EvResult schemas

Notes

To be filled by implementation agent

Summary

To be filled on completion

1.8 KiB Raw Blame History Unescape Escape