TPK4131: Industrial Logistics Systems Design
This is a new course and this wikipendium is based on the spring 2021 lecture plan.
This course is based on Excel and a sufficient understanding and use of this is required.
- Basic knowledge about the design of production and logistics systems.
- Understanding and use of relevant models, analytical methods and techniques.
- Insight into what constitute core technologies and automation in logistics.
- Fundamental understanding of report writing.
- Ability to apply aquired knowledge for developing holistic solutions within production and logistics system design.
- Ability to transform theories into practical application based on well-founded choices of relevant alternative solutions.
- Critically and independently evaluate analytical tools, methods, technical models and solutions.
- Understand the role of the production and logistics engineering in design more sustainable systems.
- Cooperate and contribute to multidisciplinary interaction.
- Communicate technical production problems and solutions.
Industrial Logistic Systems
Logistics can be defined as the control of the management of goods and information flows that a company receives, transfers and sends. Logistics manages all the flows of goods and information between the main partners of a company. The suppliers upstream and the customers downstream. It also controls the internal flows inside the company.
There are several models of logistics: production logistics (industrial companies), distribution logistics (retailers) and third-party logistics (services).
Bill of materials
A production and logistics system is an integrated system consisting of various entities that work together in order to acquire raw materials, convert these raw materials into specified final products, and deliver these final products to markets.
Design of production line and job-shop/process department systems
Assembly lines are commonly used in a mass production system. An assembly line typically consists of a number of workstations arranged in a sequence and linked by a conveyor. The workstations can be automated, e.g. performed by robots, or manual where the work is carried out by operators, or even semi-automated, where an operation is carried out by a machine but maneuvered by an operator. In order to facilitate the analysis of the line, the assembly line is usually divided into a number of zones.
A job shop is a type of manufacturing process in which small batches of a variety of custom products are made. In the job shop process flow, most of the products produced require a unique set-up and sequencing of process steps. Job shops are usually businesses that perform custom parts manufacturing for other businesses. However, examples of job shops include a wide range of businesses—a machine tool shop, a machining center, a paint shop, a commercial printing shop, and other manufacturers that make custom products in small lot sizes. These businesses deal in customization and relatively small production runs, not volume and standardization.
Job-Shop/Process department design
Calculation of Production Requirements
Based on the wanted outcome of the production we need to calculate how much input is required to reach the output we need.
The formula for then is:
If we have a desired output of
For n-sequential operations we use:
Overall Equipment Effectiveness
Based on the
A = Availability
PE = Performance
Q = Quality
We get an Overall Equipment Effectiveness (OEE)
Work shift = 480 min
Breaks: 2 x 15 min = 30 min
Lunch: = 30 min
Downtime: = 47 min
Ideal production rate = 60 pcs/min
Minutes available for production = 480-30-30-47 = 373 min
Total pcs = 19271 pcs
Defective parts = 423 pcs
Write how this works in Excel
Calculation of Number of Machines Required
Based on the desired output i.e. pcs/hour we need to calculate how many machines are required to reach this based on the Required Throughput
We say that
That gives us:
Theoretical (min) no. of machines required
Actual no. of machines required
Number of machines:
Write how to do it in excel
Calculation of Utilization rate
How much of the machine potential is utilized
From previous case:
When it comes to production lines, we use the same calculations as in the pprevious steps, only in a line with multiple machines with different functions in the production.
The thing that we need to look at in production lines is the required throughput calculation
When in a production line with i.e. 3 machines, they all have different
For machine no. 2 it's different. We need to mind the end output and quality of production for the next machine, machine no. 3, to get a relevant required throughput
For machine no. 1 we need to mind the end output divided by the quality number of the next two machines time:
Procuction Line example
Design of product family department systems: cellular manufacturing and Flexible Manufacturing Systems (FMS)
Product family department systems
A product family is simply defined as the set of all possible end-products from which the customer can make his selection. A model of a product family, termed the product family model, is then defined as a single model from which models of all end-products of the family can be derived. The product family model can serve as a foundation for the configuration process and, in order to secure that only legal configurations are selected, the model should contain restrictions about what is possible and not possible. The result of each configuration will be a model of the configured product. This model will describe the end-product to a certain degree by a set of specifications, which have to be decided during the configuration process.
Cellular manufacturing is a process of manufacturing which is a subsection of just-in-time manufacturing and lean manufacturing encompassing group technology. The goal of cellular manufacturing is to move as quickly as possible, make a wide variety of similar products, while making as little waste as possible. Cellular manufacturing involves the use of multiple "cells" in an assembly line fashion. Each of these cells is composed of one or multiple different machines which accomplish a certain task. The product moves from one cell to the next, each station completing part of the manufacturing process. Often the cells are arranged in a "U-shape" design because this allows for the overseer to move less and have the ability to more readily watch over the entire process. One of the biggest advantages of cellular manufacturing is the amount of flexibility that it has. Since most of the machines are automatic, simple changes can be made very rapidly. This allows for a variety of scaling for a product, minor changes to the overall design, and in extreme cases, entirely changing the overall design. These changes, although tedious, can be accomplished extremely quickly and precisely.
A cell is created by consolidating the processes required to create a specific output, such as a part or a set of instructions. These cells allow for the reduction of extraneous steps in the process of creating the specific output, and facilitate quick identification of problems and encourage communication of employees within the cell in order to resolve issues that arise quickly. Once implemented, cellular manufacturing has been said to reliably create massive gains in productivity and quality while simultaneously reducing the amount of inventory, space and lead time required to create a product. It is for this reason that the one-piece-flow cell has been called "the ultimate in lean production."
Flexible manufacturing systems (FMS)
A flexible manufacturing system (FMS) is a manufacturing system in which there is some amount of flexibility that allows the system to react in case of changes, whether predicted or unpredicted.
This flexibility is generally considered to fall into two categories, which both contain numerous subcategories.
The first category is called as Routing Flexibility which covers the system's ability to be changed to produce new product types, and ability to change the order of operations executed on a part.
The second category is called Machine Flexibility which consists of the ability to use multiple machines to perform the same operation on a part, as well as the system's ability to absorb large-scale changes, such as in volume, capacity, or capability.
Most FMS consist of three main systems:
1) The "Work Machines" which are often automated "CNC machines" are connected by
2) By a "Material handling" system to optimize parts flow and
3) The "Central Control Computer" which controls material movements and machine flow.
The main advantages of an FMS is its high flexibility in managing manufacturing resources like time and effort in order to manufacture a new product.
The best application of an FMS is found in the production of small sets of products like those from a mass production.
Group technology or GT is a manufacturing technique in which parts having similarities in geometry, manufacturing process and/or functions are manufactured in one location using a small number of machines or processes. Group technology is based on a general principle that many problems are similar and by grouping similar problems, a single solution can be found to a set of problems, thus saving time and effort.
The group of similar parts is known as part family and the group of machineries used to process an individual part family is known as machine cell. It is not necessary for each part of a part family to be processed by every machine of corresponding machine cell. This type of manufacturing in which a part family is produced by a machine cell is known as cellular manufacturing. The manufacturing efficiencies are generally increased by employing GT because the required operations may be confined to only a small cell and thus avoiding the need for transportation of in-process parts.
Group technology is an approach in which similar parts are identified and grouped together in order to take advantage of the similarities in design and production. Similarities among parts permit them to be classified into part families.
The advantage of GT can be divided into three groups:
Engineering Manufacturing Process Planning
Disadvantages of GT Manufacturing :
Involves less manufacturing flexibility Increases the machine down time as machines are grouped as cells which may not be functional throughout the production process.
Product Flow Analysis
Starting from the route sheets or process charts of each part/products, we identify the PMIM (Part-Machine Incidence Matrix), where
With the Rank Order Clustering (ROC) algorithm we can reorganize the PMIM in a matrix with diagonal block of 1s
- Calculate the weight of each row as follow (j = 1 ... n # of products):
Reorder the rows in descending order
Calculate the weight of each column as follow (i = 1 ... m, # of mach.):
In practise this means:
For every product
Give every coumn a binear value (2^number of rows - the row number it's on)
For product 1 on row 1:
Sum all the columns which have a value for every row
Product family identification
Material flow analysis and Layout Design
The material flow is the most important factor in a production company because products are created from materials. Only if the products are sold can the factory cover its costs. Therefore, it is imperative to move the material between the appropriate steps of the value chain directly and as quickly as possible.
When looking for a definition for material flow, you will come across different sources (VDI 2689, REFA …) though all essentially agree in their individual contexts:
The material flow is a sequence of processes ranging from the extraction of raw material via its processing, reprocessing and machining up to the finished product and delivery to the end consumer.
Basically, a distinction is made between in-house and external material flows which, in turn, has influence on the approach for material flow planning.
Whereas the external material flow is usually performed by logistics service providers in conjunction with other customer orders, the in-house material flow usually falls into the company’s own responsibility.
In most cases, the in-house material flow starts with the delivery of raw materials, parts or also subassemblies to the incoming goods warehouse and ends in the outgoing goods department with the delivery of finished or also semifinished products. Thus all transport processes between incoming and outgoing goods warehouses are part of the in-house material flow.
This can be realized by way of different transport means. On the one hand, there are personal transport means, such as forklifts, tugger trains or hand trucks, and on the other hand, there are non-personal transport means, such as roller conveyors, unmanned transport systems and racking storage and retrieval machines.
The objective is to minimize the workload associated with the material flow, as a result of which automatic transport systems are used to a growing extent.
Since there is normally no value creation in the product through the transport, despite all optimizations, the material flow should always be reduced to the transport processes that are absolutely necessary.
Maximum Punctual Flow
Layout Design Methodologies
There are many methods for the optimal layout design.
Typically their objective is to minimize the travelled distance.
Some of them are: – (Pairwise Exchange Method) – Hollier method – Graph-based method – Maximum punctual flow
Minimize the travelled distance of return flow
Graph Based Method
Layout Alternatives Evaluation
Analytic Hierarchy Process (AHP) by Saaty