System APS w planowaniu produkcji

Production planning as an official order

Many times, I have encountered a situation where workers in production told me what the production schedule should look like on their machine. They argued that the sequence could be planned differently, thus reducing the number of changeovers. They pointed out that such a schedule limits the throughput of their machine. And what did they usually do? They arranged the sequence “their way”. Is this really how it should work? Let us find out.

Production planning: how to evaluate a report?

Very often, production planning hands over the plan to be implemented for a given day or week, and it is the manager or foreman who arranges the sequence of tasks on the machine. And, from the point of view of his machine, his process, he tries to do it as well as possible. An employee on the shop floor, however, does not see all the interrelationships between interrelated production operations and material movements: what impact they have on the timeliness of execution, on the bottlenecks in the upstream and downstream process, on the stock levels at each stage of production. So how can we evaluate the production report of a given team? In terms of the volume produced? In terms of production time? In terms of the number of defects? Or maybe is it worth looking at the production report in terms of the completion of the production schedule prepared?

Production schedule: what to include?

It is crucial to be able to design a schedule that takes into account the actual interrelationships between production operations, process and material constraints and deadline requirements on all production orders. This is what advanced production planning and scheduling systems are for. The planner, when designing the schedule, must take into account at least:

  • the availability of raw materials and intermediate products
  • the availability of packaging
  • the availability of machinery and tools
  • the machine throughput including the changeover matrix
  • the planned partial yield
  • the availability of staff
  • the work plan of the staff with the accuracy of the competence matrix
  • the progress of production orders.

The figure below shows the effects of the approved production schedule.

Generated and published by the planner, the production schedule must be given the force of an official order. Therefore, its deviations and changes must be properly justified, reported and taken into account in the next scheduling session. Each of the process participants will receive guidelines, the application of which will guarantee the achievement of the process performance indicators expected and counted in the production plan.

Production planning: actors in the process

It is the task of the procurement staff to enforce the implementation of the purchasing plan. Thus, they receive a list of products which they have to provide for a specific date. If there is information that the delivery will be made on a different date than previously confirmed, it is very important that, in a predetermined, systematic way, it reaches the planner, so that he can update the production schedule.

Warehouse workers will receive a list of items that need to be prepared for a particular shift. A handling worker, a truck operator or a crane operator, will know from where and when to collect material and to which location to deliver it.

In production, the employee will in turn receive a list of tasks to be performed on his machine or at the position to which he has been assigned today by the manager or shift foreman. The production schedule takes into account the actual availability of machines and tools as well as process limiting parameters. Therefore, if nothing critical happens, the worker is responsible for sticking to the schedule given to him. He has time reserved for the operation on a specific production order and for changeovers, in accordance with the changeover matrix developed.

Production process: performance vs. production schedule

On the basis of my experience, I can say that the implementation of production in accordance with a predesigned schedule also reduces the number of defects arising in the production process. Managers, production engineers and foremen have time to deal with the task for which they were appointed, i.e. supervising the production process. They do not have to deal with putting out fires resulting from constant changes in the plan. Reducing plan changes also means reducing unplanned material movements on the shop floor. Movements that can cause material damage.

A good production schedule is also an effective, correct and, above all, feasible plan of work for employees. The plan will take into account not only different working time systems, settlement periods, forms of employment, compliance with the Labour Code and internal regulations, the validity of tests and qualifications, but it will also be correlated with production schedules. As a result, each employee receives a schedule that ensures the performance of pre-planned production operations.

By comparing production plans with their implementation, we get data that allows us to update production technologies. This enables us to build increasingly better production schedules. The process stabilises over time, but in my experience, I have to say that it is endless. All the time, we have to take care of the quality of technological data.

Unimplemented production plans

In fact, failure to perform according to the schedule prepared by the planner results in the company failing to meet its performance and business indicators. And it’s not just a matter of failing to meet the production plan and, therefore, failing to deliver customer orders on time. It also affects related production processes, as well as work in departments supporting production, sales, procurement, maintenance and quality control. The necessity of catching up on the plan forces excessive exploitation of machines and equipment, which increases their failure frequency.

Other effects often include:

  • a significant reduction in the quality of products
  • the increase in the number of defects
  • lowering of quality control standards
  • increased costs related to the downtime of employees and production stands, additional overtime pay, production failure or costs incurred in the production of defects.

The company may also bear additional costs in the form of contractual penalties paid to customers for failure to meet delivery dates.

Designing not only a feasible plan but also an optimal schedule is, therefore, a key task in a manufacturing company. You “only” need to implement it, and all the business indicators you assumed will be met. And it turns out that the man stands in the way of achieving the goals. It is not uncommon for employees working on the first production shift to choose orders that are more suitable for them. Employees on subsequent shifts have less and less choice. Why do they do this? Because they are asked to account, for example, for the quantity and time of the finished parts. They themselves are afraid of the risk of defects, so they choose products requiring lower qualifications and less commitment. Often, the employee on the machine decides to change the sequence of production orders so as to reduce the number of changeovers. From the point of view of the entire process, this may not be the optimal solution.

Production scheduling, feasible and optimal

It is worth considering the accountability of employees in terms of the degree of implementation of the production plan. If the planner has designed a production schedule which provides us with certain business indicators (timely completion, minimum production cycle, adequate level of inventory, satisfactory production efficiency and optimal number of changeovers), then let us make sure to implement it as much as possible.

I am convinced that the degree of completion of feasible and optimal production schedules has a significant impact not only on the timely delivery of orders to customers, but also on the costs borne in production, business indicators achieved and productivity of the company. It is easier for us to select employees for the tasks; also, we are able to optimise the load on production means and eliminate bottlenecks. We can reduce or even eliminate production waiting time for components and reduce warehouse stocks. Thus, we will become a more reliable partner for our customers.

Artur Głodek
expert in the business analysis department
eq system

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