Model overview

The data model has two parts: what describes the operation, which changes little (plants, resources, processes), and what is planned, which changes every day (orders, proposals, plans).

Project
 ├─ Plant ──< Resource >── Resource type
 ├─ Process (template) ──< Process task
 │                            ├─ resource requirements (with alternatives)
 │                            └─ precedences (with minimum and maximum waits)
 ├─ Product (process + properties)
 ├─ Order ──< Order line (quantity, due date) ──> Product
 └─ Proposal (start date, status, base plan)
       └─< Planned task (resource, start, end, fixed)

Entity	What it describes	Page
Project	A planning problem with its configuration: time unit, default objectives and constraints	This one
Plant, resource type, resource	Who does the work, where and with what capacity	Resources
Process and process task	What steps a job has, in what order and with which resources	Tasks and processes
Product, order, line	What has to be done and by when	Orders and dates
Proposal, current plan	Computed plans and the accepted plan	Proposals and current plan
Planned task	Each task with its resource, its start and its end	Result of a plan

Project configuration

Field	What it is
Input unit	The unit in which durations are given (minute, hour, day or week)
Planning unit	The unit the plan works in
Default objectives	The objectives applied if a proposal does not specify otherwise
Default constraints	The active constraints
Maximum computation time	How long the computation of a proposal can take; the best solution found is returned

Properties and formulas

Resources, tasks and products can carry their own properties: length, weight, speed, number of parts. Durations, quantities and the choice of resources can be formulas over those properties.

cutting duration = part length / machine speed
valid resources  = machines whose load capacity ≥ part weight

Formulas are validated before computing: a reference to a property that does not exist or a cycle between formulas is flagged as an error.