Production Planning and Control

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The production planning and control ( PPS ) is a branch of production economy that the production technology and the economy computer science is especially close. The PPS deals with the operational, temporal, quantitative and, if necessary, spatial planning , management and control , as well as the management of all processes that are necessary in the production of goods. Technical framework conditions are planned in the work preparation . This is divided into the two areas

  • Work planning or production planning and which defines the actual technical framework conditions such as the machines, tools and workplaces as well as the
  • Work control which is identical to production planning and control.

overview

Production planning and control is still the core of every industrial company today. The focus is on optimizing the entire production system. Production systems describe the holistic production organization and contain the presentation of all concepts, methods and tools that, in their interaction, make up the effectiveness and efficiency of the entire production process.

The PPS is divided into production planning, which plans the processes in the medium to short term , and production control , which uses this planning to approve and control the orders . Both areas are intertwined and are mostly combined in one area of ​​responsibility, especially in small to medium-sized companies.

In the literature, there is no consensus on a uniform naming and distribution of the individual steps of the PPS. These are often listed in varying degrees of detail and were tabulated, systematized and compared by a team of authors.

Parts of the PPS, the production planning , the material requirements planning , the scheduling and capacity planning , the order release and order monitoring .

The Aachen PPS model provides an overview of the tasks of the PPS. Here there is a breakdown into core, network and cross-sectional tasks. While the core tasks such as For example, if the production program and production requirement planning are to drive the processing of an order, the cross-sectional tasks (e.g. controlling, order management) serve the cross-departmental integration and optimization of the PPS. Against the background of the organizational structure of production networks with distributed, local company units, a strategic design level is necessary as the basis for strategic / tactical planning. These planning elements are summarized under the network tasks.

Another PPS model is the Hanoverian supply chain model .

As a rule, the PPS processes are supported by PPS systems ; these are often an integral part of an enterprise resource planning system. The first approaches to integrated systems were developed in the early 1970s by, among others, IBM with COPICS .

Traditional PPS systems are based on a successive planning concept. The tasks of production planning and control are broken down into sub-problems that are solved one after the other. However, the transitions between the individual points are often fluid.

The massive spread of technically complex products and the constant shortening of product life cycles have led to a steadily increasing need for disposal for some years, which leads to the increasing relevance of dismantling planning and control (DPS). The DPS is largely designed in the same way as the PPS.

Production planning

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According to Erich Gutenberg , production planning can be divided into

Production scheduling

In the context of production program planning, one deals with long, medium and short-term planning, whereby parameters such as capital commitment , deadlines and the ability to correct errors are decisive, whether they have a strategic or operational character. In the case of long-term planning (from 3 years), the question of market segments and corresponding products must be clarified that should form the focus of entrepreneurial activities. In the medium term ( quarterly , annual planning), product groups are planned so that in the short term (during the year) only the number of products to be manufactured has to be decided.

The creation of a production program for varied and complex products is an iterative planning process that extends over a long period of time. From this, specific methods and procedures for planning production programs have developed, as is the case, for example, in automobile construction. Here, the long-term sales per country or sales market are first estimated using different stochastic forecasting methods. The sales-oriented sales plan is created from the forecast sales, from which the production-oriented production plan is derived. Sales and production plans do not yet contain any specific products, but only aggregated production quantities for the various product types (e.g. cars , trucks , buses ) and their product classes or product families (e.g. VW Golf , VW Passat , VW Polo etc. ). The production programs containing the real vehicle orders from customers or dealers are only created relatively late.

The sales plan is market-related, while the production plan is plant-related and at the same time describes the production capacities. The sales and production programs will only be created in the short term. First, based on the actual customer orders, the market-oriented sales program is created, from which the production program is derived. Due to the large number of variants and due to restrictions (e.g. production or delivery capacities), the production program is smoothed, whereby the aim of production is to complete all customer orders in good time so that they can be handed over to sales or the customer as agreed. Most companies are now striving to only manufacture products according to customer orders ( build-to-order ) and thus come close to mass customization . On the basis of the binding production program for end products ( product ), production programs ( production order ) for the required production parts and the delivery programs ( delivery schedule ) for required purchased parts can be derived. To do this, the production programs must be broken down into their components (parts and assemblies) using parts lists .

Material requirements planning

Starting from the primary requirement (salable and demanded end products), the material requirements planning determines which quantities of raw materials or raw parts, intermediate products, individual parts and assemblies (= secondary requirements ). are needed to cover primary needs. For this purpose, the components that make up the product must be documented in parts lists or work plans. For all components (individual parts and assemblies) that appear in the parts list, there should also be a technical drawing that describes the current construction status in order to ensure the consistency of commercial, production-related and constructional data and processes. The product is successively broken down into its components with the help of these parts lists and work plans; There are different processes for exploding the parts lists, which are based on the type of parts list display. From the parts list explosion, you first get the need for higher assemblies and built-in parts. With the help of disposition parameters (e.g. lot size, lead time / delivery time, ...), the production and delivery programs for the assemblies can be derived from this. These are in turn broken down into smaller assemblies and built-in parts with the help of parts lists, which in turn form the basis for the next level of material requirements planning, etc. etc. The last level of the parts list is always the built-in parts; these are either purchased parts that have to be procured from other manufacturers, or manufacturing parts that are manufactured by the company itself. For the production of these 'in-house parts', the necessary raw parts, materials and raw materials must be purchased, which are documented in a work plan (see in- house production or external procurement ).

In branches of industry with technically complex and varied products, such as the automotive industry, the determination of the secondary requirements is particularly time-consuming. It first requires the resolution of the product definition from the individual customer order with the help of a variant parts list . Due to the large number of variants, the product is defined using features, with a product configurator helping the customer to select his desired features and pointing out the permitted / inadmissible combinations of features. Using the product definition, which is a mandatory part of the customer order, an order-related parts list can be generated for a single product from a complex or maximum parts list, which contains all the required assemblies and parts. The summary of all singular secondary requirements determined in this way represents the starting point for the determination of the net requirement as well as the formation of orders for purchased and manufactured parts. Various restrictions must be taken into account, through which the determined secondary requirements are adjusted in terms of time and quantity to the existing production and transport conditions: Production and transport capacities, batch sizes, working hours, transport times, etc.

Production process planning

This includes the

  • Lot size planning
  • Scheduling and capacity planning
  • Sequence planning and detailed scheduling

Lot size planning

Lot size planning determines how many orders for a product can be combined into one lot so that the sum of the production, storage, set-up and cleaning costs is minimized. The optimal batch size cannot always be realized due to insufficient capacities and has to be split at the expense of costs.

Scheduling and capacity planning

As soon as the quantities to be produced are known, scheduling begins. The earliest and latest dates for the implementation of individual work steps are planned using lead time scheduling . Then the question must be clarified whether the necessary capacities for the production program are available. This is roughly planned in capacity scheduling. In the event of capacity bottlenecks, individual work steps must be postponed to other periods. As soon as this is done, roughly scheduled orders can be passed on to production control.

Sequence planning and detailed scheduling

The detailed planning determines which machines are assigned to certain jobs. Short-term production control tasks are primarily to be seen in connection with short-term changes in the reality of orders or capacities :

  • unplanned failure of a machine or system or an employee
  • unexpected high priority customer orders .

Since the interrelationships are multi-dimensional, the tasks of production control are increasingly being carried out with corresponding software systems. These not only allow the stated tasks and boundary conditions to be carried out efficiently and conveniently, they also enable the planner to be highly flexible and provide a high level of transparency about the current status of occupancy and deadlines in production.

While some systems use methods of operations research to optimize the results, practice-oriented systems are characterized by heuristic working methods taking into account work process-related priority rules that largely correspond to the understanding and view of the production planner.

The results are machine allocation plans and resource allocations of devices , tools , NC programs and allocations of employees.

Sequence planning of multi-level procedural batch processes

When planning multi-level production processes ( batch operation ), not only are the orders for end products (semi-finished goods for the neutral warehouse or filling orders) arranged serially on different production lines. Rather, “sub-orders” for the individual partial production stages and their interdependencies must also be considered and planned. Particularly in batch operation, precise knowledge of the production systems and their procedural possibilities (stirring, heating, cooling, distilling, evacuating, etc.) is required. However, minimum and maximum quantities per batch - depending on the container - must also be taken into account. Product-specific parameters such as batch separation for interim storage, processing periods of intermediate or partial products or interruption possibilities during production also play a major role in process engineering and are included in the sequence planning. It goes without saying that the cleaning and set-up times for all system parts, depending on the material, are considered.

Planning systems for complex production processes also combine sub-production stages of different types. In the case of production stages of the "batch character" type, there is a fixed occupancy time, whereas in the case of the "continuous character" type, the system occupancy time is derived from a response, throughput or delivery rate [e.g. E.g .: kg / hour]. A clear presentation of the planned and ongoing production takes place in the dynamic planning board. Here, the target specifications from the production plan are compared with the status from production and displayed as a Gantt diagram . The integrated monitoring reports any delays and calculates new remaining terms.

Production control

Production control is the initiation, monitoring and securing of the execution of the released orders . The production (and assembly ) area is also called production control . After the machine occupancy has been determined through detailed scheduling, the orders are initiated by providing work records for the company. The monitoring is carried out by suitable real-time feedback systems . Saving is the corrective intervention in the event of deviations such as quantity, deadlines and quality.

Order approval

The roughly scheduled orders received from production planning are finely scheduled here. Some concepts for order approval are Kanban or load-oriented order approval (BoA principle).

Order monitoring

A prerequisite for monitoring the production processes is feedback on the current status of production, in short, operating data acquisition . The feedback either via direct input at workstations or via Betriebsdatenerfassungs- (BDE) and Manufacturing Execution Systems (MES). This confirmation data is not only important for production control, but also for gross wage accounting , material inventory updates, concurrent costing and post-costing, quality control and maintenance for maintenance planning .

Conception of production planning and control systems

Production planning and control according to the push principle (pushing principle)

To cope with the extensive responsibilities of the operational production planning and control are (PPS) systems used in business practice has long been computerized production planning and control, which operate according to the push principle, as the production orders in the production process are pressed. PPS systems regularly access a database of the production area, in which all data on the products, production processes and resources are stored.

A so-called throughput scheduling of the entire production process is carried out on the basis of all real or planned orders with the respective completion dates . This is done with the help of defined or determined average times for individual processing steps. All orders are thus divided into their work steps and start and end times are specified for these and the resulting start and end times for the orders are calculated.

Following the lead time scheduling, the resulting capacity load is determined for each resource and the capacity requirements are compared with the available capacity . As part of a capacity load equalization, attempts are made to eliminate overloads, if necessary by postponing the deadlines for non-critical orders and by scheduling overtime. In the following, an order sequence with an exact start and end date is defined for each work group or machine. This schedule is then used to control the flow of information and materials in production.

Production planning and control according to the pull principle (pulling principle)

In the case of production on demand (pull principle), production control begins - in contrast to the push system - with the production program for the products that have been ordered by a customer or a dealer. Then only the required parts and assemblies are procured from the upstream production areas or from the supplier, who in turn procure only the necessary parts and assemblies, etc. etc. The pull principle requires a corresponding (re) organization of the entire production process and the delivery processes ( see also SCM ).

The basic idea is that each department only ever produces as many units of a product as are actually required by the subsequent (consuming) departments (production on demand). This principle works best for standard products with regular requirements, few variants and a material flow-oriented arrangement of requirements.

Self-controlling control loops (production areas) connected one after the other can be installed and the short-term production control can be taken over by the employees of the respective production area. Each control loop has a sink in which material is brought to the downstream control loop and used there, and a source that is filled by the upstream control loop.

Chained production and delivery systems can also be installed, which supply each other according to fixed rules and principles. The following delivery variants can be distinguished:

However, it must be noted that, depending on the information speed, a whiplash effect (bullwhip effect) may occur, as will be soon here on security in order to avoid a shortfall. The bullwhip effect is through the concept of cumulative quantity be avoided. This is used in large-scale production, for example between automobile manufacturers and suppliers, as a production and procurement control process based on the pull principle.

See also

Production planning

Production control

Reference models

literature

  • Wilhelm Dangelmaier : Theory of production planning and control. Springer, Berlin 2009, ISBN 978-3-642-00633-3 .
  • Wolfgang Domschke, Armin Scholl, Stefan Voß : Production planning: procedural organizational aspects . 2nd Edition. Springer, Berlin 2005, ISBN 3-540-63560-2 .
  • Horst Glaser, Werner Geiger, Volker Rohde: PPS - Production planning and control: Basics - Concepts - Applications . Gabler, Wiesbaden 1992, ISBN 3-409-23906-5 .
  • Hans-Otto Günther, Horst Tempelmeier: Production and Logistics . 7th edition. Springer, Berlin 2007, ISBN 978-3-540-74152-7 .
  • Karl Kurb : Production planning and control in Enterprise Resource Planning and Supply Chain Management . 6th edition. Oldenbourg, Munich 2005, ISBN 3-486-57578-3 .
  • Herbert Jodlbauer : Production optimization, value creation and customer-oriented planning and control . 2nd Edition. Springer, Vienna / New York 2008, ISBN 978-3-211-78140-1 .
  • Pere Mir-Artigues, Josep González-Calvet: Funds, Flows and Time: An Alternative Approach to the Microeconomic Analysis of Productive Activities . 1st edition. Springer, Berlin 2007, ISBN 978-3-540-71290-9 .
  • Herfried M. Schneider, John A. Buzacott, Thomas Rücker: Operative production planning and control: Concepts and models of information and material flow in complex manufacturing systems . Oldenbourg, Munich 2005, ISBN 3-486-57691-7 .
  • Günther Schuh (Ed.): Production planning and control: Basics, design and concepts . 3. Edition. Springer, Berlin 2006, ISBN 3-540-40306-X .
  • Hans-Peter Wiendahl: Business organization for engineers . 7th edition. Carl Hanser, Munich 2010, ISBN 978-3-446-41878-3 .
  • Günther Gäpfel: Production management: operational production management . de Gruyter, Berlin 1982, ISBN 3-11-007450-8 .
  • W. Herlyn: On the problem of mapping products with many variants in the automotive industry . VDI Verlag, Düsseldorf 1990, ISBN 3-18-145216-5 .
  • W. Herlyn: PPS in automobile construction - production program planning and control of vehicles and assemblies . Hanser Verlag, Munich 2012, ISBN 978-3-446-41370-2 .
  • Andreas Opitz: Computer-aided investment planning - a strategy for planning engineers in manufacturing companies . Chemnitz University of Technology, Chemnitz 2011 ( online, PDF ( memento from October 12, 2013 in the Internet Archive )).
  • H. Stadler, C. Kilger: Supply Chain Management and Advanced Planning . 3. Edition. Springer Verlag, Berlin / New York 2005, ISBN 3-540-74511-4 .
  • Paul Schönsleben: Integral logistics management. 7th edition. Springer Vieweg, Berlin / Heidelberg, 2016, ISBN 978-3-662-48333-6 .

Individual evidence

  1. ↑ Tobias Meudt, Andreas Wonnemann, Joachim Metternich: Production planning and control (PPS) - an overview of the literature on the different classification of PPS concepts. (PDF) (No longer available online.) In: Publication. TU Prints, June 22, 2017, formerly in the original ; Retrieved July 19, 2017 .  ( Page no longer available , search in web archives )@1@ 2Template: Toter Link / tuprints.ulb.tu-darmstadt.de
  2. ↑ H.-P. Wiendahl: Business organization for engineers. 7th edition. Hanser Verlag, Munich 2010, p. 249 ff., In particular p. 257.
  3. ^ Gutenberg's work - Erich Gutenberg Society eV - Herford. Retrieved March 5, 2019 .
  4. ^ W. Herlyn: PPS in automobile construction. Hanser Verlag, Munich 2012, p. 121 ff.
  5. ^ W. Herlyn: PPS in automobile construction. 2012, p. 57 ff.
  6. ↑ W. Herlyn: On the problem of mapping products with many variants in the automotive industry. 1990, p. 75 ff.
  7. ↑ H.-P. Wiendahl: Business organization for engineers. 2010, p. 315 ff.
  8. ↑ P. Schönleben: Integral Logistics Management. 2016, p. 250 ff.
  9. ↑ Peter Kürble, Marc Helmold, Olaf H. Bode, Ulrich Scholz: procurement, production, marketing . Tectum Wissenschaftsverlag, January 18, 2016.

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