Was ist Advanced Planning and Scheduling (APS)?
Advanced Planning and Scheduling (APS) is a software-supported approach to detailed production planning. It takes into account machine capacities, material availability, shift models, and technical restrictions in real-time, thus enabling realistic completion dates.
Definition of Advanced Planning and Scheduling
Advanced Planning and Scheduling (APS) is a software-driven approach to production and detailed planning. The system takes into account machine and workstation capacities, material availability, qualifications, and technical restrictions and sequences. It calculates a realistic and optimal production sequence based on the target processing times per product for a company's workstations and their capacity. This creates transparency regarding dependencies, deadlines, and bottlenecks in manufacturing.
Introduction: Why Production and Detailed Planning Are Becoming Increasingly Complex
Modern production environments are characterised by a high variety of products and short delivery times. Customer requirements are changing rapidly, and automation is increasing. Production planning must consider thousands of dependencies, resources, and restrictions simultaneously. This is where Advanced Planning and Scheduling (APS) comes in. For the implementation of such software to be successful, it requires expertise, consistent action, and perseverance.
In many companies, it's clear: traditional planning methods are reaching their limits – this is also confirmed by the Fraunhofer IPA in its analysis of Advanced Planning and Scheduling. This becomes particularly clear when manufacturing steps are dynamic, failure-prone, and interdependent. APS enables data-based, capacity-oriented detailed planning that reflects the actual state of production.
Limitations of Classical Production Planning
Classic planning tools work with static assumptions. Typical examples include Excel spreadsheets, manual lists, or simple ERP capacity modules. They have several structural limitations:
- They cannot represent complex interrelationships and dynamic changes.
- Bottlenecks, conversion times, shift models, and staff qualifications are not taken into account.
- Short-term disruptions cannot be intercepted by them – online data will not be processed.
- Planning is carried out against unlimited capacity, plan data is maintained manually.
In practice, this leads to flawed planning and unreliable deadlines. In highly complex manufacturing environments, this results in enormous coordination effort—with direct impacts on costs and deadline transparency.
Advanced Planning and Scheduling
Advanced Planning and Scheduling refers to an integrated approach to production and detailed planning. The methods used enable realistic scheduling. They take into account actual capacities and existing restrictions. Disruptions in the production process can be quickly resolved. Every replanning is fully transparent. This makes Advanced Planning and Scheduling a central component of modern production control.
Objective of an APS system
An APS system takes on the task of automating and optimising complex planning decisions. Capacities, resources, restrictions and dependencies are taken into account in the best possible way. The result is efficient, transparent and flexible production control.
The key objectives at a glance:
- Schedule and capacity planning: Machines, workstations and resources are optimally utilised. Overloads are avoided, and realistic completion dates guaranteed.
- Prioritising orders Urgent or important orders will be prioritised. Changes and reschedules can be implemented flexibly.
- Simulation of planning scenarios: The planner can test alternatives and their impacts. Risks are identified early, and the best solution is selected.
- Minimising bottlenecks and setup times The APS system identifies problem areas early and ensures a smooth production process.
- Data-driven decisions All production data will be processed. Planning will be faster, more accurate, and more transparent.
Distinction from ERP and rough planning
An ERP (Enterprise Resource Planning) system controls a company's entire business processes – purchasing, production, warehousing, sales, and finances. It manages master data for materials, suppliers, and locations and forms the basis for initial rough planning.
High-level planning in ERP systems often works with unlimited capacity. It checks whether customer demand can be met by stock or production. Actual capacity limits of machines or personnel are disregarded. The result: unrealistic production plans, deadline overruns, and resource overload.
An APS system builds upon ERP data and delivers significantly more detailed and realistic planning. It always plans using target times for products against limited capacities and maps all actual restrictions – technical constraints, material availability, and personnel qualifications. The result is reliable completion dates instead of theoretical wishful dates.
How does Advanced Planning and Scheduling work?
Planning based on deadlines, restrictions, and capacities
An APS system creates a detailed production plan, taking into account all relevant restrictions. To do this, the system analyses the current situation by downloading master data, determining the status of available resources, and then analysing and optimising the order backlog located in the system. This is done in the following steps:
- Machine capacities: The system checks which machines are available and what capacity they offer and when.
- IntendedTimes: The anticipated standard time for processing the product is determined from the master data and scheduled as occupation time on the machine or workstation.
- Tools and jigs: Special manufacturing fixtures are considered as resources; bottlenecks are identified early.
- Shift models: Different working hours and shift systems are factored into the planning.
- Material availability: The current availability of raw materials and components is being checked to avoid production stoppages.
- Arming and changing times: Times for machine conversion or tool changes are factored in.
From these factors, the software calculates an optimal sequence of production steps and uploads these start and end dates back into the ERP. This then provides a realistic plan with deadlines for each manufacturing step for production.
Optimisation algorithms in APS
Special algorithms are used for calculating an optimal plan. Typical methods include heuristics, mathematical optimisation models, and rule-based approaches. These are processed step-by-step in a configurable planning run and generate an efficient and realistic production plan.
Typical heuristics in a planning run include:
- First-In-First-Out (FIFO) Orders are processed in the order they are received.
- Shortest Processing Time (SPT): Orders with the shortest processing time will be prioritised in scheduling.
- Earliest Due Date (EDD) Orders with the earliest delivery date will be scheduled first.
- Priority Rule Orders with higher priority are dealt with preferentially, for example, with urgent customer orders.
- Mínim Temps Lliure Orders with the smallest time buffer between completion and delivery date are scheduled first.
The aim in all cases is to make optimum use of capacity and to meet delivery deadlines reliably.
Frozen Horizon: Please do not touch!
A „Frozen Horizon“ in APS (Advanced Planning and Scheduling) systems refers to a period in the future during which no further changes are permitted to the production plan. Within this defined horizon, orders and resources are firmly scheduled, and adjustments such as rescheduling, postponement, or new orders are only considered after the Frozen Horizon has elapsed. The purpose of this concept is to ensure planning security and stability in production. This allows manufacturing processes to run reliably, as short-term changes are excluded, and employees can depend on the established sequences.
Role of real-time and planning data
The performance of an APS system depends directly on the quality of the master data used. The following information is crucial:
- Target processing timeThe target time is the time that an APS plans as occupation time for a workstation. If this time is incorrect or deviates from the actual time, APS software will not provide a realistic plan. Shit in – shit out!
- Manufacturing progress: Timely feedback from production is the basis of all reliable planning. If the APS does not know how far an order has progressed, accurate planning is also impossible.
- Fault reports: Information on downtime enables rapid adjustments to be made to the schedules for machines and workstations.
- Online feedback: Quantities, quality, and actual times improve planning accuracy, as the APS is thus supplied with the correct information online at all times.
- Resource availability Shortages can only be identified early with real-time availability data, such as stock levels and shortage lists.
Who Real-time manufacturing data captured, This avoids manual errors and provides current planning foundations. Three key principles apply here:
- Master data must be continuously maintained.
- Target times or planned times must be regularly compared with actual times.
- Automated data capture via an online MES system prevents errors and keeps planning data up-to-date.
Only if these prerequisites are met can an APS system optimally control production.
Detailed planning in production
Was bedeutet Feinplanung konkret?
Detailed planning defines the exact timeline in production. It takes into account all available resources – machinery and personnel. Specifically, it encompasses:
- Production step sequencing based on target times
- Assignment of layers and machines
- Inclusion of alternative fallback resources
- Co-ordination of successive manufacturing processes
The goal is a realistic and feasible production plan that ensures a smooth process.
Short-term adjustments and re-planning
In production, unforeseen changes occur repeatedly. Machine failures, delayed materials, staff shortages, or shifted priorities are typical examples. An APS system allows for quick and straightforward plan adjustments. The impact of any rescheduling becomes immediately visible.
How Advanced Planning and Scheduling Manages Disruptions and Bottlenecks
Advanced Planning and Scheduling makes it possible to transparently identify disruptions and bottlenecks. Alternative resources are taken into account, and the impact of problems is assessed in real time. An integrated MES System provides the necessary real-time data from production.
Overview of the benefits of Advanced Planning and Scheduling
Improved delivery reliability
Planning based on actual capacities allows for reliable delivery dates. Production processes become stable, and schedule adjustments are significantly reduced. Advanced Planning and Scheduling therefore ensures greater planning certainty and minimises unexpected disruptions.
Better resource utilisation
An APS system makes more efficient use of machinery and personnel. Bottlenecks are identified early, optimal sequences are calculated, and unnecessary setup times are minimised. Output increases — without additional resources.
Reduced lead times
Materials and resources are provided in a coordinated manner. Waiting times and intermediate storage are minimised. Overall, production runs faster and more smoothly.
Conclusion: Advanced Planning and Scheduling as the Key to Efficient Production Planning
Companies need to design their production processes to be flexible, transparent, and efficient. Advanced Planning and Scheduling (APS) offers a suitable approach for this – for realistic detailed planning and reliable deadlines. The quality of master data is crucial, as it forms the foundation of all successful planning.
An APS system increases punctuality, flexibility, and resource efficiency. Prerequisite: Feedback from manufacturing must be reliable and up-to-date – for example, via an MES system. Without real-time data, a realistic plan is not possible. The operational level and planning must be synchronised.
IGH Infotec AG supports companies with solutions in the fields of MES and mobile data acquisition to ensure the connection between planning and manufacturing – thereby increasing transparency and competitiveness.
More transparency and reliable production data? Contact us now.
