Master production schedule

The production program includes the totality of a company's products in the type and quantity and also determines the location of the products to be produced for a specified time or specified time interval. Distinction is made between the horizon and the maturity of the production program:

• ( 1) the strategic production program describes the basic product fields and product types that wants to offer ( up to ten years ) the Unternehmem in the distant future;
• ( 2) the tactical production program describes to specify exact quantities to be produced of the products or product groups for a medium production period in a summary manner, without the individual product variants; This is also known as a production plan.
• (3) the operative production program includes the exact quantity of all product variants of all final goods from which the manufacturing and assembly programs for the self- produced assemblies and individual parts BOM are derived according to. The production period moves - depending on the product - between one week and one month. For complex products ( ships, aircraft, railway), the period can be much longer. Here one also speaks of the production program.

The production program is a primary requirement for the source of the deterministic identification of needs (see a secondary requirement) Represents the operational and business objective is to create a production program with maximum contribution margin. This is added value moderately sought through optimal utilization of resources. Starting point and basis of production planning is the one the sales program that is based on sales plans, sales orders or sales estimates, and on the other the remaining stock of finished products. A taking into account the individual capacities broken down on the portions of the manufacturing production program is referred to as a production program.

• 4.1 A bottleneck in the production
• 4.2 Several bottlenecks within the production

Production planning in multi-variant products

The creation of a production program is a planning process that extends over a long period in richly varied and complex products. First, the paragraph is each country or market estimated from the global sales plan is created. For this production plan is derived, the 'only' get the production quantities for product types and product families. The final production program is created based on the production plan then, in which the real customer orders are included.

This process can be particularly good to understand in the automotive industry. Here the sales and production plans are created in long-term first area in which 'only' the number of vehicle types according to the auszulastenden production capacities are planned. These sales and production plans are time- and product- related successively refined over the course of the planning process by which products are specified more accurately. At the end of the planning process production programs for the individual production plants are created, where are the actual vehicle orders from customers, dealers and importers. When you schedule the orders, the number and types of vehicles ordered frequently do not cover with the available capacities. Therefore, the orders must be distributed in time and place. Because of the variety and due to restrictions ( production and delivery capacity ), the production program to be smoothed on the premise that all orders are yet to produce in time so that they can be the sales or the customer handed over as agreed (see leveling (Business Administration ) ).

The consistency of the production programs between vehicles, assemblies and sub-assemblies is ensured that the planning concepts of products and production programs are based on an ideal algebra.

It is therefore desirable to establish possible only vehicles to customer order (build -to-order ) and to get as close to the Mass Customization. For the production process must be organized so that as many variants of the product and / or of modules without interruption can be made in a production facility, a production cell or in an assembly line. In the automotive industry, this type of production organization and flow manufacturing mainly in the form of assembly is very widespread. This results in specific methods and procedures of production planning and control have developed in the automotive industry that are particularly necessary for the control of product variants.

The planning of the optimal production program must be based on existing capacity and bottlenecks. As long as the plant is not operating at full capacity, so there is underemployment and also all manufactured products can be sold easily without bearing structure, production planning ( PPPL ) has little significance. Each product with a positive contribution margin contributes to the improvement of the company's results and should therefore be included in the production program.

Bottleneck

The bottleneck (English bottleneck, "bottleneck ") is a stagnation in the production process, which occurs due to capacity shortages. Capacity is the maximum of the production process available in a given time unit number of personnel, machines, devices, tools and spaces. A bottleneck arises in the production process when the waiting capacity is not sufficient to meet the production requirements. The possible utilization of production capacity will exceed the available capacity.

Bottlenecks mainly caused by three factors:

• Through from the outset for sufficient capacity:

At the start of production must be composed of a maximum output capacity planning content to produce sufficient expected to meet product demand. Bottlenecks can be provoked by lean production when intentionally scarce capacities are available.

• By fluctuations in capacity:

Since capacities are usually not constantly available (eg in staff turnover, machine failure ) may occur through capacity bottlenecks fluctuations quickly at full capacity when they are surprised by a too low capacity.

• Due to high stress in the production:

A prolonged, excessive strain on equipment and personnel can lead to increased default risks ( machine failure, illness) and redeemed at low capacities.

Species

We distinguish internal bottlenecks as a result of operational capacities and external bottlenecks, particularly for just- in -time production can occur in procurement logistics. Internal factors of production bottlenecks are not only a production factor alone, but also by the interaction of mismatched ( harmonized ). To avoid bottlenecks, the operational factors of production must be dimensioned and harmonized so that they can withstand temporary overloads (such as overtime, shift operation).

Effect

Bottlenecks can occur frequently in business; the elimination of a bottleneck brings the occurrence of other bottlenecks with it. It therefore did not matter to eliminate all bottlenecks, but they coordinated. This is the purpose of the constraint-based scheduling. The bottleneck determines the maximum possible utilization per unit of time, it limits the performance of the whole chain. The overall operational capacity of the sector with the smallest capacity - the bottleneck - limited. Occurring bottlenecks can lead to damage caused by defective production, production losses or penalties.

Constraint-Based Scheduling

The constraint-based scheduling is one next to the capacity planning for operational employment planning. In contrast to capacity planning, the constraint-based scheduling is not based on the theoretical maximum capacity, but focuses on the acquisition, production or sales process limiting factors. Sectors where bottlenecks occur, called minimum sector. The bottleneck of the minimum sector limits the overall operational capacity. From the minimum sector comes from an operational performance impairing effect, it is essential to reduce by constraint-based scheduling. The aim of the constraint-based scheduling is to optimize the production flow. Companies with standardized mass products require a different kind of constraint-based scheduling than those with job-related or order production.

Strategies to eliminate bottlenecks are

• The staff: overtime, Springer, time work, shift work;
• In products (procurement and sales ): Warehouse;
• In machines: production supervision and temporal target values ​​for individual production steps.

Bottleneck calculation

Can not be eliminated bottlenecks in the short term and is fully utilized before, the question arises which congestion strategy by a company. It is generally the possibility of prioritization, which first the products are produced with the highest profit contributions. Alternatively, other strategies are also used.

A bottleneck in the production

If a single bottleneck before ( for example, machine capacity), then can not be produced all products. It comes to the non-production of products that would actually generate a positive contribution margin. This is taken into account -stealing on the identification of the opportunity costs of the displaced product in the calculation. A method for determining the optimal production program with an effective multi- product restriction are relative piece margins. Set the respective quantity required coefficients in relation to the achievable by the product contribution margin.

Several bottlenecks within the production

Exist in the plurality of production constraints, then a simple analysis based on the opportunity cost is no longer possible. For the mathematical solution is a simultaneous model is to be used ( for example, the simplex method ). Because a solution can be determined graphically, but this solution method is limited to a maximum of 3 variables ( number of displayable dimensions).

To avoid production losses are in the automotive industry with the help of rules that relate to the product configuration, the products distributed through production works, daily and assembly lines that the bottlenecks balanced and the distribution of the products are balanced on the assembly lines.