Planning and Scheduling – A Key Enabler of Industry 4.0 Transformation

Industry 4.0 envisages a flexible network of connected Cyber Physical Systems (CPS), working autonomously and self-optimizing performance across the network. Optimizing the sub-components of the system does not necessarily optimize the overall system [1]. To achieve a synergy, there is a need for a more global optimization of the entire system.

Decisions like what to make, when to make, and where to make have a system-wide impact and fall into the domain of Planning and Scheduling (P&S). Without the ability to make these decisions from a global view point, it will not be possible to realize the full benefits of Industry 4.0 initiatives.

The global supply chain requires a new level of P&S sophistication, Planning and Scheduling 4.0. The next generation of P&S solutions make this level of integration and automated decision making possible.

The Planning and Scheduling Evolution

Much like all of manufacturing, Planning and Scheduling (P&S) has gone through multiple generational cycles:

• P&S 1.0: For much of history, production was organized by manually generated plans and schedules.
• P&S 2.0: Since the advent of computers, mainframe applications and custom spreadsheets have been used to creating production plans and schedules. These digital tools can be considered the first generation of P&S systems and they are still used by the majority of organizations to handle their planning and scheduling as of 2018. The main limitation of P&S 2.0 systems is their inability to handle the detail and complexity of today’s manufacturing environment. As a result, the output of these systems is far from optimal and considerable manual intervention is required to adjust the generated plans and schedules before they can be implemented.
• P&S 3.0: Advances in algorithms, the availability of low cost, high-performance computing and the ubiquity of network services enabled the next generation of P&S solutions. Optessa MLS V1 – V6 are exemplars of this generation, characterized by sophisticated data models to describe real-world detail, and state-of-the-art algorithms to solve the resulting complexity. Browser based interfaces replaced the need for client specific interfaces. These systems require little-to-no manual adjustment to generate plans and schedules. The optimal quality of these plans and schedules ensure that a high return on investment (ROI) and significant cost savings are often realized just weeks after the implementation of the P&S solution.
• P&S 4.0: P&S 3.0 systems represented a dramatic improvement over capabilities of earlier generation P&S systems. Today, new technological advances are transforming manufacturing and driving the need for P&S systems that support even greater integration, automation, and transparency. Solutions, like the Optessa MLS V7+, represent the next generation of P&S systems and are key enablers of Industry 4.0 initiatives in manufacturing.

Technology Drivers Impacting Planning and Scheduling

Here are some of the ways that the same technologies that drive Industry 4.0 innovation, are also transforming Planning and Scheduling:

• Algorithms & Data Models: Global optimization of plans and schedules, scaling to accommodate problems of extensive scope and complexity, and real-time rescheduling.
• Artificial Intelligence / Machine Learning: Autonomous execution of Planning and Scheduling processes, real-time response to changes.
• Internet of Things (IoT): Makes available high-resolution, high-volume data which provides timely and accurate information on the status of the factory, as well as the supply chain.
• Big Data & Analytics: Processes large volumes of data and provides the inputs needed to generate global, real-time plans and schedules.
• Digital Twin / Simulations: Goes hand in hand with P&S 4.0, since a digital twin that does not model Planning and Scheduling cannot capture the operation of the factory.
• Cloud: On-demand, affordable computing with the capacity to execute P&S 4.0 algorithms.
• Cyber-Physical Systems: Empower users to solve the most complex Planning and Scheduling problems.
• Digital Supply Chain Management: Enables a global, multi-tier approach to optimizing the supply chain.
• Blockchain: Secure and auditable communication between autonomous systems.
• Mobility: Smart phones and tablets, bring the power of P&S 4.0 to users wherever they might be.

Planning & Scheduling 4.0

The defining characteristics of Industry 4.0 are Connected, Transparent, Proactive, Agile and Optimized [2]. P&S 4.0, a vital component of Industry 4.0, also displays these characteristics.

• Being Agile means responding to changes in customer’ requirements or changes in operating conditions.
• Being Connected enables co-operation between systems.
• Being Proactive allows planners to anticipate changes and prepare accordingly.
• Being Transparent enables the sharing of useful and actionable information.
• Being Optimized ensures that all actions are coordinated to realize defined goals.

The following illustrates several new use cases that P&S 4.0 enables:

Global Optimization

Planning and scheduling are among the most computationally challenging of all engineering problems, and need to be broken into sub-problems which are then solved. While this enables solutions that can be deployed in practice, as discussed earlier, some degree of optimality is lost [1]. The enhanced capabilities of P&S 4.0, in terms of deeper and wider visibility into the supply chain, and advances in algorithms and computing means that sub-problems can be combined to yield more global formulations, and yield ever more high-quality plans and schedules. A case in point is the multi-tier planning of the entire Supply Network. Another is the Virtual Flow Line (VFL) capability of Optessa MLS V7+ which can holistically optimize multiple production stages.

Real-Time Rescheduling

A Proactive and Agile factory requires a Proactive and Agile P&S system. Connectivity provides the P&S 4.0 process with accurate and timely data. Conversely, the benefits of IoT and Big Data cannot be not fully realized without P&S 4.0, and other analytic systems that leverage this data.

Real-time data, in the form of orders, forecasts, inventories, and resource status updates, can be coupled with Analytics to determine if the current plan or schedule is no longer optimal, or (in extreme cases) even buildable. Given advances in algorithms and computing, P&S 4.0 can re-optimize the plan or schedule on the fly. Artificial Intelligence / Machine Learning enables the system to autonomously respond to a full range of failure events that impact execution.

High Fidelity Scheduling

A great volume of data is being collected by manufacturing organizations as they advance their digitization initiatives. Unfortunately, beyond tracking and visualization, that data is not being fully exploited to produce actionable decisions. High resolution data, such as accurate counts of parts and finished goods inventories, can be used to as inputs to Planning and Scheduling models of great detail and complexity. From this data, P&S 4.0 can generate high- fidelity schedules that are both buildable and optimal.

The above examples illustrate the transformational capabilities of P&S 4.0, and how a Connected, Transparent, Proactive, Agile and Optimized P&S is a vital component to realize Industry 4.0.

References

[1] J. Hunter, “Optimize the Overall System Not the Individual Components,” The W. Edwards Deming Institute Blog, 8 November 2016. [Online]. Available: https://blog.deming.org/2016/11/optimize-the-overall-system-not-the-individual-components/. [Accessed 19 July 2018].

[2] R. Burke, A. Mussomeli, S. Laaper, M. Hartigan and B. Sniderman, “The smart factory, Responsive, adaptive, connected manufacturing,” 31 August 2017. [Online]. Available: https://www2.deloitte.com/insights/us/en/focus/industry-4-0/smart-factory-connected-manufacturing.html.