Model 2.3.0

Research centre

Trace the calculation contract, evidence, limitations and materials needed to reproduce model 2.3. ProcuraCost does not select a procedure for the user or assume the direction of the cost difference.

01 / Model contract

What the model calculates and under which conditions

AssumptionsVersioned parameters, ranges and the evidence status of each value.Calculation methodHow the inputs are checked, calculated and recorded with the result.Mechanisms and evidenceAn explicit separation of source claims, assumptions and model outputs.

02 / Research and replication

From hypothesis to reproduced result

Research agenda and paperQuestions, hypotheses and the limits of empirical inference.Code and replication packageThe public implementation, tests and deterministic model 2.3 artefacts.

03 / Application context

Materials outside the cost calculation

Practitioner materialQuestions about process friction, requirements, accountability and adoption.TeamThe roles and competencies of the people developing the project.

01 / shared boundary

Legal and governance boundary

Both alternatives use the same procedure family, initiation date and legal rules. Mandatory PZP periods are locked, documented and identical on both sides of the comparison.

02 / two designs

Workflow and contract design

Each alternative has its own map of activities, dependencies, effort, waiting and non-labour cost. Contract design remains a separate dimension and is not replaced by a technology label.

03 / explicit calculation

Cost and coverage record

The engine adds role effort, non-labour cost, delay cost and only explicitly monetised contract dimensions. The record also identifies factors outside monetisation and the source of each assumption.

04 / inference boundary

Assumptions, sources and practitioner observations

External evidence, retained assumptions and practitioner observations have separate statuses. Procurement&Beyond material informs implementation questions but does not set cost-model parameters or ranges.

How to read the result

Delta is the cost of the formal sequential alternative minus the cost of the adaptive compliant alternative. Low, central and high values form a declared scenario stress range, not a probability estimate. The outer range combines opposite endpoints of the two alternatives. Crossing zero alone does not establish a sign reversal under shared assumptions.