1 - Modelling

Question 1

Production planning is the planning of:

Answer 1

• acquisition of the resources and raw materials
• production activities required to transform raw materials into finished products

Question 2

Supply chain planning

Answer 2

Supply chain planning extends the scope of production planning, by considering and
integrating procurement and distribution decisions

Question 3

A first model: The model identifies:

Answer 3

1 the objects to be manipulated (products, resources, time periods, …)

2 the data associated with the objects (demand, capacity of resources, …)

3 the decisions (decision variables or variables) to take about the objects to propose a
solution to the problem

4 the constraints to be satisfied by the decisions to define a feasible solution for the problem

5 the objective function which provides a way to evaluate or compare feasible solutions and
to select the best or optimal solution among the feasible ones.

Question 4

Model components

Answer 4

1 Indices represent similar objects.
Examples:
The index t represents an element in the set {1, . . . , NT} of time periods
The index i represents an element in the set {1, . . . , NI } of products

2 Parameters classes contain similar data.
Example:
The data demand(i,t) defines the demand for all products i and time periods t

3 Variables classes contain similar variables.
Example:
The variable prod(i,t) defines the production level decisions for all products i and time
periods t

4 Constraint classes contain similar constraints.
Example:
The constraint demand_satisfaction(i,t) defines the demand satisfaction constraint for
all products i and time periods t

5 Objective function expresses the aim of the model.
Example: profit maximization

Question 5

MTS

Answer 5

MTS (make-to-stock) production policy: the plant production must be able to meet
demand directly from stock

Question 6

MPS

Answer 6

1 MPS (Master Production Schedule) plans the production at the finished product
level (packaging level) to meet forecast demand and safety stock

Question 7

MRP

Answer 7

MRP (Material Requirement Planning) system determines when and how much to
produce of each intermediate product (mixing and preparation) or raw material over
the schedule horizon