Manufacturers more and more feel the pressure of coping with a more volatile and uncertain demand. As demand signals become more unpredictable, bullwhip effects may propagate and intensify this volatility along the entire supply chain, wreaking absolute havoc upstream, ultimately, onto the manufacturing shop floor itself. The need for a more agile, responsive, and flexible supply chain is becoming more urgent. One way to deal with this volatility is through a Shop Floor Scheduling System.

Basically, a Scheduling System focuses on decision support for execution and control at the shop floor level: order/lot sequencing, equipment availability and setups/changeovers are determined, taking into consideration the equipment and material allocations which optimize one or more objectives. As constraints at an operational level become more complex, the ability to synchronize all of them into consistent scheduling results becomes increasingly difficult and with it, the need for such a system surfaces.  

At the shop floor level, a Scheduling System can  offer significant benefits, including a radical decrease in the scheduling workload; the reduction of WIP (Work in Progress); shorter and more reliable cycle times; as well as an increase in equipment efficiency. Additionally, a well implemented Scheduling System will empower the planning department to quickly respond to any external variation on demand, considering every shop floor constraint from setup, equipment and material availability to maintenance schedules and expiration dates, coupled with the confidence that the results are being tailored to their specific objectives.

Similarly, data captured from the shop floor will make sure that any disturbance or variance can be quickly and seamlessly incorporated. Gone is the risk for unattended equipment to be overlooked when planning the next day’s work, and gone is the scrambling for a solution whenever a major setback occurs – all of this is taken care of by the Scheduling System in a business as usual manner!

Yet, despite this amazing business proposition, it would be wise to consider what some of the possible challenges associated with the implementation of a traditional Scheduling solution are: dangers of high solution ownership costs, long implementations or ultimately misfits between the solution and the shop floor.   Let us go over some of these issues.

Scheduling as a part of Supply Chain Management

As we began this article, we arrived at the shop floor scheduling issue by looking at the supply chain as a whole. When considering a shop floor Scheduling solution, the approach should encompass the same constraints.

It is necessary to have an end-to-end picture of how each level of planning will be managed by a business IT system, as well as to understand what functions fall under each planning level and how these different levels communicate to synchronize information. In fact, technologically, one of the biggest challenges in the development of Advanced Planning and Scheduling (APS) systems is an effective decomposition and orchestration of the end-to-end problem into sub-problems [1].

Therefore, it stands to reason that the Scheduling solution should be understood as a piece of the puzzle in terms of supply chain management: should any other planning level either be missing, or incorrectly connected, the puzzle is incomplete.

This means that trying to use a Scheduling solution as a standalone ‘silver bullet’ to solve the company’s planning issues, by taking over the responsibilities for Production Planning for example, will inevitably result in a misfit. Instead, a complete Scheduling strategy must tailor each planning level to its own scope and challenges, considering Sales & Operations Planning (S&OP), Demand Planning, Inventory Planning, Production Planning and Order Promising – the key to success being a close, quick, and effective integration between these different planning levels.

Proximity to Execution

If the Scheduling solution sits at the bottom of the Supply Chain Management Hierarchy (Figure 1), it is only natural to think that it must be built on an accurate model of the shop floor. Additionally, as these plans will be applied and enforced to a smaller or greater degree, it is important for the schedule to reside in a system close to the Execution. This is also very relevant when it comes to a Planned vs Actual analysis, particularly in terms of identifying bottlenecks and constraints which conditioned the schedule’s fulfillment. As the concept of Industry 4.0 matures, additional possibilities may open. For example, a smart manufacturing shop floor may be able to trade-off the initial assignment for a certain order with the live conditions of the equipment, such as its setup; should the initial decision prove unfavorable, the system would determine the best local alternative on the fly.

For all of these reasons, it is important to consider that Scheduling should reside in a system where all of these inputs and signals coming from the shop floor can be accurately captured in a timely manner. 

Figure 1 – Supply Chain Hierarchy. Source: T. Miller, “Supply Chain Frameworks: A Constant In The Midst Of Change in Supply Chain Management and Logistics: Innovative Strategies and Practical Solutions,” [2]

Change Management

An inevitability whenever a new business IT solution is being implemented is Change Management; should Scheduling be given any special attention in this regard?

When included as a native functionality of a Manufacturing Execution System (MES), Scheduling differs in that it must be co-owned by multiple stakeholders:

  • Results, Delivery Dates and Order Cycle Times are now directly connected to the quality of the process information present in the MES itself. As such, Manufacturing and Process Engineering are indirectly key stakeholders on the generation of the schedules, as they provide the process parameters on which it will be based.
  • The level of enforcement of the schedule’s execution for different equipment as well as the decisions of when to override the schedule and when/who should regenerate the schedule are now issues that will affect Planners and Production Supervisors.

As such, it is critically important to ensure that these stakeholders are included in the creation of the Scheduling strategy, and that they are present throughout the implementation and roll out of the system.

The Future

Having a clear strategy on how to evolve the company’s supply chain may also leverage the long term returns on implementing Scheduling. To give some context on this topic, let’s take a look on how Gartner understands the evolution of Supply Chains through their Logistics Maturity Model [3].

Figure 2 – R. v. d. Meulen. “5 Stages of Logistics Maturity.” Gartner. [3]

In this model, a Supply Chain may be classified into one of five stages of maturity, with the journey starting with independent, “siloed” departments making unaligned decisions (Stage 1) to a broader network which synchronizes in real time all information for all relevant stakeholders, and is able to put each decision in terms of delivered customer value (Stage 5).

What can this mean in terms of Scheduling? It is natural that, for a first implementation, requirements may focus on delivering the Production and Planning departments a solution that replaces manual planning processes, based on spreadsheets and whiteboards, by an automatic scheduling system that is able to consider all applicable constraints (therefore, Stage 1), while also providing feedback to a higher level system, such as an ERP, on the expected execution (moving here into Stage 2, as demand and supply start to be aligned).

However, as we move on to the later stages of the supply chain maturity model, greater focus is put into integrating all planning levels, ensuring that any input is propagated in real time throughout the entire structure and having unified, customer-oriented metrics. Therefore, it is possible that Scheduling’s main role, within the scope of a mature Supply Chain, shifts into a validation system, instantly reacting to demand changes occurring at a much higher level and guaranteeing that a trustworthy “Go/No Go” signal is sent all the way back to the Sales department. Of course, such a vision will require many moving pieces to work as one, but a reactive and powerful Scheduling module will certainly be part of it!


A Scheduling System can be a valuable part of your overall response to supply chain issues.  A good scheduling system will be integrated with both your business systems, as well as your production systems, to provide you with the ability to quickly respond to changes in demand, and employ the necessary iterations in operations for accurate execution.

Scheduling can be deployed iteratively, avoiding the ‘big bang’ project overload so often seen with enterprise projects.  Especially in today’s trying environment, the ability to respond and implement changes in demand provides companies with an undeniable competitive advantage. For more information on Critical Manufacturing’s understanding of Scheduling, please visit


[1] A. Lupeikiene, G. Dzemyda, F. Kiss, and A. Caplinskas, “Advanced planning and scheduling systems: modeling and implementation challenges,” Informatica, vol. 25, no. 4, pp. 581-616, 2014.

[2] T. Miller, “Supply Chain Frameworks: A Constant In The Midst Of Change in Supply Chain Management and Logistics: Innovative Strategies and Practical Solutions,” 2016, pp. 3-17.

[3] R. v. d. Meulen. “5 Stages of Logistics Maturity.” Gartner.


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