implementatielast

Implementatielast is a metric used in software engineering to quantify the burden associated with implementing a new feature or change within a software system. The concept is a composite score intended to reflect not only code effort but also integration, testing, deployment, data migration, and coordination needs.

Origin and term: The term combines Dutch words implementatie (implementation) and last (burden). It is used in some agile and systems engineering discussions to emphasize burden beyond estimated coding time.

Calculation: Typically IL is computed as a weighted sum of factors: CodeComplexity, IntegrationComplexity, DataMigration, TestingRequirements, DeploymentImpact, CoordinationEffort. Each factor scored on a 0-5 or 0-10 scale. Weights sum to 1 or 100; IL is normalized to 0-100.

Applications: Used during planning to compare feature options, inform design decisions (e.g., prefer modular changes to reduce IL), and help prioritize backlog; can be tracked over time to monitor maintainability.

Limitations: Subjective; depends on team experience; may underrepresent maintenance tail or long-term risk; best used with calibration and multiple observers.

See also: Technical debt, effort estimation, risk assessment, software metrics.