Scholz GmbH & Co. KG

Scholz GmbH

Scholz GmbH & Co. KG was founded in 1974 and remains a family-owned business based in Kronach, Germany. Scholz specializes in manufacturing precision plastic components for microtechnology, gear technology, and medical technology. A standout feature is its top-tier expertise in plastic mold production, with all molds made in-house. Scholz is known for its exceptional product quality, achieved through the use of 80 high-performance injection molding machines and advanced peripheral equipment.

The Initial Situation

In 2017, Scholz GmbH & Co. KG produced around 40 new molds. Their ERP system is Microsoft Navision. Since they lacked dedicated scheduling tools, they had to rely on Excel to manually schedule and control their processes.

Mold production involves manufacturing a variety of electrodes for sinker EDM machines, while different metal parts are produced in parallel. All these components then come together for pre-assembly and final assembly. Creating a single mold requires scheduling hundreds of processes, many running in parallel. At the same time, multiple projects are managed simultaneously, with several orders being processed on the same set of machines.

With such complex production processes, including both in-house and outsourced manufacturing, manually scheduling production sequence couldn’t be done without significant losses in quality, flexibility, and the ability to simulate outcomes.

Operational Challenges at Scholz:

• Scheduling processes became significantly more complex as the number of molds increased and external factors came into play.
• Precise completion dates couldn’t be provided, leading to the need for extra buffer times, which extended delivery times.
• Start dates for follow-up orders were set based on experience, resulting in a push-production.
• Unsynchronized production of individual components led to long lead times.
• High stagnation caused large inventories, especially of semi-finished products.
• The scheduler’s main task was organizing work for today and tomorrow rather than actual scheduling.

As scheduling complexity grew due to a surge in orders, process optimization became necessary. This required significant improvements in both effectiveness and efficiency.

Choosing Asprova

In mid-October 2017, Scholz’s managing partners, Mr. Martin Rebhan and Mr. Karl-Herbert Ebert, reached out to Asprova GmbH (formerly AG), described their challenges, and sought advice on implementing an APS system. The following systematic approach was recommended for selecting an Advanced Planning & Scheduling tool:

• Creating an APS specification sheet (mid-November 2017)
• Setting goals
• Data analysis (routings, BOMs, orders, etc.)
• Developing a prototype using real customer data 
• Presentation of the prototype and validation of results (mid-December 2017)

Requirements for Production Scheduling

The most important requirement for APS software is the ability to fully reflect the “reality” of the factory—meaning it must account for all product characteristics, processes, process rules and restrictions, as well as scheduling constraints. Capturing Scholz-specific rules and restrictions for mold-making posed a challenge, due to factors such as:

• Multi-level finite capacity scheduling with APS system: for every single process, both main resources and sub resources must be scheduled simultaneously, taking finite capacities into account. In several processes, one main resource can have multiple sub resources. For example, the main resource could be a machine, while sub resources include two different fixtures and an operator.
• Automatically selecting alternative machines with different capabilities in terms of product dimensions and material properties.
• Handling process loops: certain materials return multiple times to specific resources and must always be processed in the correct order.
• Synchronizing parallel and converging processes.
• Accounting for raw material availability.
• Considering employee availability: shift schedules and vacations.
• Managing outsourced production, such as hardening (pickup/delivery schedules).
• Automatic process selection, such as deciding between in-house or outsourced production based on specific criteria.

Implementation and Results

After successfully validating the Scholz-specific prototype, Scholz purchased the Asprova APS software license at the end of 2017.

• The kick-off workshop took place in early January 2018.
• Followed by MES interface setup.
• Basic settings in Asprova APS. 
• Defining dispatching view and scheduling logic for individual processes, resources, and orders.
• Full-scale, automated production scheduling with Asprova APS started about 3 weeks after the kick-off (parallel phase).
• By the end of February 2018: full go-live of automated scheduling with the Asprova system. Since then, Excel has no longer been used for scheduling.
• Highly realistic and feasible sequence scheduling.
• Synchronous processes.
• Accounting for material availability. 
• Calculating the production of 60 molds, up to 12 months in advance, within just 20 seconds.
• Visualizing the status of all orders 12 months ahead through order Gantt chart, resource Gantt chart, operation table, load graph, and inventory graph.
• Delivering reliable completion dates for individual molds.
• Gradually adjusting and improving the data structure since implementation.

Both the management team, Mr. Martin Rebhan and Mr. Karl-Herbert Ebert, as well as Asprova users and schedulers, are thrilled with the new Asprova APS software.