M. Case study: Machine tools (M)

M. Case study: Machine tools (M)

Step by step guide to environmental assessment with the LCA to go tool:

1. Define the scope for the env. ass. of the Machine tool2. Collect data on the LC of the Machine tool3. Model the Life cycle of the Machine tool4. Enter data of the Machine tool into the online LCA to go tool5. Review the result for the Machine tool6. Interpret the result & derive improvements for the Machine tool

Case study: Machine tools (M)M.1. Define the scope

Substeps:a. Define the goal of the studyb. Define the functional unitc. Define the reference flowd. Define the product system and the unit processese. Draw a process treef. Define the system boundaries of all 5 life cycle stages g. Define other requirements

Case Study Machine toolM.1.a. Defining the Goal for an environmental assessment of the Machine tool

Why: To generate an environmental profile of the machine tool and identify the key environmental issues. Who: Designers and engineers working on the upgrade of the current & development of future models of the machine tool.What: Use the results to derive product improvements and compare different generations of the machine tool with respect to their environmental performance.

Case Study Machine toolM.1.b. Defining a Functional unit for an environmental assessment of the Machine toolThe product function of the Machine tool is to machine materials. There are a wide range of machine tools such as grinding, drilling, milling, (laser) cutting or electro discharge machining tools.Since all fashion different workpieces, the only relevant functional unit they all share is the operation of the machine in a specified shift regime over the lifetime of the machine. A shift regime defines the amount of time the machine tool spends in the three main operating states, „Production“, Ready“ and „Standby“ in a fixed period.The Functional unit is therefore defined as:One machine tool over the entire machine lifetime, in a declared shift regime, specifying the number of shifts over the lifetime and the amount of time spent in the three main operating states „Production“, „Ready“ and „Standby“ in a shift.

Case Study Machine toolM.1.c. Defining a Reference flow for an environmental assessment of the Machine toolThe reference flow is a measure of the amount of product needed to realize the function as indicated in the functional unit. Since the functional unit is the operation of the machine tool over one hour in a specified shift regime, the reference flow contains all the materials, energy and processes necessary for this.Materials contained in the machine tool, Energy and materials needed for manufacturing of the machine tool, Transport of the machine tool and the packaging needed, the electricity consumption while the machine tool is in use.

Case Study Machine toolM.1.d.Defining the Product system and Unit processes for the Machine toolDefine the individual processes involved in the machine tool over its lifetime• Material: Components of the machine tool and the contained materials

• Foot: Cast iron, Sand• Housing: Al, Flat glas, Polycarbonate• Workpiece-holder: Steel, Electric motor• Tool-holder: Steel, Electric motor• Electronic control unit: Cu, Electronics, PP

• Manufacture: Energy used and waste generated• Electricity used in production• Steel and Iron shavings as waste

• Distribution: Method and packaging• Transoceanic freight ship and truck• Wood crate for shipping

• Use: Energy use and material consumption in the use stage• Electricity required in use stage

• End of life: Recycling possible• Recycling of the materials declared in the Materials stage

Case Study Machine toolM.1.e. Drawing the process tree for the Machine tool

Foot

Sand

Cast Iron

Housing

Polycarbonat

e

Glass

Al

Workpiece holder

Electric

motor

Steel

Tool holder

Electric

motor

Steel

Electronic control unit

PP

Cu

Electronic

s

End of Life*(incl. energy)

Use*(incl. energy)

Distribution*(incl. transport & packaging)

Manufacturing*(incl. energy & manufacturing waste)

*It is customary not to show Energy and Transport processes in the process tree. Data collection must include these processes.

Materials

Case Study Machine toolM.1.f. System boundary of the 5 life cycle stages for the Machine tool• Materials

• Includes natural resource extraction and pre-processing of raw materials used in the machine tool.

• Excludes the transport & packaging of the raw materials from pre-processing to the manufacturing plant due to data gaps.

• Manufacture• Includes the energy needed for processing of the materials as delivered to the

manufacturer and the assembly of the machine tool at the manufacturing plant. (e.g. Drilling, welding, …)

• Includes the waste generated in the manufacturing process.• Includes the resource consumption needed in manufacturing (e.g. oil, welding gases, etc.)

• Distribution• Includes the shipment from the manufacturer to the customer as well as packaging.• Excludes the energy needed for packaging or the setup at the customer site.

• Use• Includes the electrical energy and the operating resources during the entire lifetime of the

machine tool. Several shift regime scenarios are considered.• End-of-Life

• Includes energy and consumables needed for recycling. Benefits are included in the materials stage through the choice of recycled materials as input.

• Excludes energy needed for disassembly and transport of materials to recycling facility.

Case Study Machine toolM.1.g. Other requirements for the System boundary for the Machine tool• Temporal boundary:

• Latest available data• Geographical boundary:

• Material sourcing and Manufacture in Europe. Global Distribution and Use. Representative data to be used.

• Technological boundary:• Focus on one technology / specific type of machine tool only

Case study: Machine tools (M)M.2. Collect Data

Substeps:a. Identify necessary datab. Define the depth and quality of data neededc. Identify & keep track of data sourced. Identify and track the data quality

Case Study Machine toolM.2.a.i. Identify necessary data for the environmental assessment of the Machine tool

Materials Manufacture Distribution Use End-of-Life

Necessary

data

Type and amount of material included in the machine tool

Energy needed for manufacture

Amount and type of waste generated

Point of manufacture and point of delivery (Geographical distribution of sales)

Transport mode

Packaging

Electricity consumption in the use stage

Recyclability

Case Study Machine toolM.2.a.ii. Defining the rule for mass inclusion for the Machine tool

Materials contained in machine tool

Respective mass

[kg]

Cumulative mass as a

percentage of total mass

[%]Cast iron 13000 66,5%Steel 3120 82,5%Cooling & Lubrication Unit

250095,3%

Electronics for Control Unit

50097,9%

Electric motor 150 98,6%Aluminium 120 99,3%Copper 60 99,6%Polypropylene 40 99,8%Transformer 20 99,9%Flat glass 10 99,9%Polycarbonate 10 100,0%Full PC Set 5 100,0%Estimated total mass 19535

Decision rule for mass inclusion:

99% of total weight

Case Study Machine toolM.2.b. Define the depth and quality of data needed for the environmental assessment of the Machine tool

Materials Manufacture

Distribution Use End-of-Life

Depth

and quality of

data necessary

Heavier parts more relevant, Electronic parts relevant, Cut-off criteria 99% cumulative weight

Rough sum of total electricity for manufacturing, divided by the number of machine tools produced

Estimate of shavings waste (material and amount) per machine tool

Location of production facility and rough geographical distribution of customers

Typical mode of transport (can vary depending on geographical location of customer)

Typical packaging (can vary depending on mode of transport or geographical location)

Energy consumption needs to be divided into three operating states: Production, Ready, Stand-by (incl. an indication of the time spent in each operating state in an average shift regime)

Is the machine tool easily recyclable?

Case Study Machine toolM.2.c. & M.2.d. Identify & keep track of the data source and the data quality for the environmental assessment of the Machine tool


Data

source

Engineering department


Marketing and Sales department



Data

quality

(DQI)

Robust Indicative Illustrative Robust Indicative

Case study: Machine tools (M)M.3. Model the Life Cycle

Substeps:a. Review available data and bring it into a useful format, making assumpti

ons where necessaryb. Develop Scenarios for the Distribution stagec. Develop Scenarios for the Use staged. Develop Scenarios for the End-of-Life stage

Case Study Machine toolM.3.a. Review available data and bring it into a useful format, making assumptions where necessary for the Machine toolMaterials Manufacture

Distribution

Use End-of-Life

The data obtained from the bill of materials is grouped by material in a list

The information on the total yearly electricity consumption of the production facility is divided by the total number of machine tools produced in one year to obtain the energy consumption per machine tool.

The total waste generated in the manufacturing process in one month is also divided by the total number of machine tools produced in one month to obtain the waste production per machine tool.

Information on the geographical distribution of sales is used to build a distribution scenario.

Electricity consumption figures are collected separately for each general operating state and used to calculate the total consumption in the use scenarios.

Information on the recyclability of the machine is used to chose the End-of-Life scenario

Case Study Machine toolM.3.b. Distribution scenario development for the environmental assessment of the Machine tool

A single distribution scenario is developed:In this example, the machine tool is produced in Germany, and delivered to Sweden. The machine tool was transported from Germany to Sweden. The transport distance is assumed to be 1000km by road transport.

Case Study Machine toolM.3.c. Use scenario development for the environmental assessment of the Machine tool

To evaluate the entire life cycle of the machine tool, one must assume certain use scenarios. In this case study, a common scenario for a production site in Sweden is assumed. In the LCA to go tool, you can add up to 3 different scenarios.2 Shift regime, Sweden: Production 12 h/d, Ready 4 h/d, Standby 2 h/d, Off

6 h/dHours spent in different operating states according to use scenario

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Production Ready Standby Off

ProductionReadyStandbyOff

Case Study Machine tool

• Iron, Steel, Aluminium, Copper

• Electric motor, Electronic control unit,…

Recycling

• Polycarbonate, Polypropylene,…

Incineration

• Sand...

Landfill

This Scenario consists of different paths for each raw material. Usually the big components of the machine tool such as most metal parts and electronic components are easy to recycle. In contrast to these parts, Plastics will usually go to incineration, and some inert materials will be disposed on landfills.

M.3.d. End-of-Life scenario development for the environmental assessment of the Machine tool

Case study: Machine tools (M)M.4. Enter data

Substeps:a. Enter data for all 5 life cycle stages and define data qualityb. Understand why the data is needed and what happens with the entered

data

Case Study Machine toolM.4.a. Enter data for all 5 life cycle stages for the Machine toolA video tutorial on how to enter data into the online tool for machine tools is available at:

Watch a demonstration video

The following slides will give you a short overview on the rough and detailed assessment. Based on this case study you will see how to enter the data for the 5 Life Cycle Stages: Materials, Manufacturing, Distribution, Use, and End-of-life.

https://www.dropbox.com/sh/n8zv52rr52vh7wj/Aj5sKQ1Yx9

https://www.dropbox.com/sh/n8zv52rr52vh7wj/Aj5sKQ1Yx9

Case Study Machine toolM.4.a.i. Rough assessment / Detailed assessmentThe LCA to go tool works as a two step iterative process. The first step is to do the rough assessment, through which we can identify the major environmental impacts. The second step is the Detailed assessment where we will focus on the environmental hotspots. Following the results or improvements, the Detailed assessment can be repeated.

Rough assessment Results Analysis

Detailed assessment Results Improvemen

ts


M.4.a.ii. Rough assessment It only takes 10 minutes.

The rough assessment will give us a first impression of the environmental profile of the machine tool. Thereafter we can decide which data should be improved in the detailed assessment later.

Before enterign the data, we have to register and log in to the web tool. We create an new product, and indicate the main specifications of the machine tool. In this case study, we investigate a grinding machine. We select the industrial sector “machine tools”, define the machine tool: “Grinding Machine” and choose the option “Rough assessment”.


M.4.a.iii. Life Cycle Stage 1: Materials

The main materials and supplier parts of our example are shown in the list above. We add all the main materials in the “LCA to go” tool. For example, in this case study, the parts of the machine tool, such as the Workpiece-holder, the Tool -holder, and the Machine-foot contain approximately 13.000kg iron.

Main materials & Parts:- Cast iron: 13.000kg- Steel:3.120kg- Aluminium: 120kg- Electronics: 500kg- Electric motor: 150kg


M.4.a.iv. Life Cycle Stage 1: Materials

We add the supplier parts into the “LCA to go” tool.

Main materials & Parts:- Cast iron: 13.000kg- Steel:3.120kg- Aluminium: 120kg- Electronics: 500kg- Electric motor: 150kg


M.4.a.v. Life Cycle Stage 2: Manufacturing

In this example there are 2.000 kg waste from manufacturing in the form of metal chippings.

The machine tool is produced in Germany. 25.000 kWh are consumed in manufacturing for diverse metal working processes and for assembly.


M.4.a.vi. Life Cycle Stage 3: Distribution

The machine tool is delivered to Sweden by truck, we select the option “Overland”. In the rough assessment a distance estimate is made by the tool.For delivery, the machine tool is packed into PE-foil. We enter the approximate amount of packaging material used.


M.4.a.vii. Life Cycle Stage 4: Use

The electrical power consumption is taken from the product data sheet for the three different operating states.

The manufacturer use the machine tool 250 working days per year and produces on average 6 parts per hour.

The exact modelling of the use stage is important for the robustness of the results. As previous investigations have shown, the major environmental impact of machine tools comes from the use stage.


M.4.a.viii. Life Cycle Stage 4: Use

12 hours per day the machine tool is "Processing”, 4 hours per day it is “Ready for operation”, 2 hour per day on “Standby”, and 6 hours it is switched “Off”.


M.4.a.ix. Life Cycle Stage 5: End-of-Life

We assume a realistic End-of-life scenario. It is safe to assume for machine tools that the great majority of contained materials can easily be recycled, we select the option “Recycling”.

Data Quality: The Data Quality Indicator

We enter the Data Quality Indicator for each life cycle stage and define whether the data is “Robust”, “Indicative”, or “Illustrative”.

Case Study Machine toolM.4.a.x. Analysis, Results: Rough assessment

It can be clearly seen that the major environmental impact comes from the Use Stage. Typically a machine tool is a use intensive product.

We have to be sure that we have the most robust data for the most important life cycle stages. In this case study we have identified the environmental hotspot, but the data is only “Indicative”, so we will try to collect further data and improve the level of detail and robustness of the result, through the Detailed assessment.


M.4.a.xi. Detailed assessment

We create a new product and choose the option “Detailed assessment”.

In this model we use more detailed data and focus on the stages with the biggest environmental impacts identified in the rough assessment to achieve a more detailed and robust environmental profile. The results will enable us to draw the right conclusions and identify the fitting improvement options.


M.4.a.xii. Life Cycle Stage 1: Materials

We define the main components and the contained materials of the machine tool. The machine tool consists of 9 components: the Workpiece-holder, the Tool-holder, the Machine-foot, the Housing, the Control cabinet, 3 predefined supplier parts and the Oil mist extractor.Below you can see the materials contained in the Workpiece-holder and 3 predefined supplier parts.


M.4.a.xiii. Life Cycle Stage 1: Materials

The Oil mist extractor is not a predefined supplier part, therefore we have to define it in the tool.

In this case, the transport distance from the manufacturer to our plant is 1 000 km.Once the transport distance has been defined, the oil mist extractor will appear in the list of user-defined supplier parts, and we add the materials and the processes that are required to produce it.


M.4.a.xiv. Life Cycle Stage 2: Manufacturing

We add the main manufacturing processes that are used at our own manufacturing plant and the weight of material that is removed in chipping processes such as Milling, Drilling, and Turning, as well as the amount of material that is processed in non-chipping processes such as Sheet rolling or Wire drawing.


M.4.a.xv. Life Cycle Stage 2: Manufacturing

Additionally, 1000 kWh manufacturing energy is required to assemble the machine tool.

200 kWh overhead energy per machine tool are estimated for Air Conditioning, Lighting, Heating the manufacturing line,...


M.4.a.xvi. Life Cycle Stage 2: Manufacturing

In this case, 9.3% of the material input is wasted in manufacturing.


M.4.a.xvii. Life Cycle Stage 3: Distribution

The machine tool is distributed to Sweden by truck, the transport distance is assumed to be 1000 km.

For distribution the machine tool is packed into 150 kg PE foil. The End of life scenario here refers to the packaging material. It can either be Recycled, Incinerated or sent to Landfill


M.4.a.xviii. Life Cycle Stage 4: Use

We enter the correct location and the corresponding electricity grid mix.

As seen in the rough assessment, the use stage is the most important life cycle stage. Inaccuracies will have a huge impact on the results.

From measurement according to ISO 14955 we derive that the machine tool needs 30 kW electrical power in “Processing”, 10kW in “Ready for operation” and 0.3 kW in “Standby” modes.


M.4.a.xix. Life Cycle Stage 4: Use

A Shift regime scenario describes the use of the machine tool. In the Ddetailed assessment, three scenarios can be defined to investigate different use intensities, create a better understanding of the impact over the lifetime and customize the result to specific conditions.


M.4.a.xx. Life Cycle Stage 4: Use

The machine tool needs 1 m3/h compressed air in the operating state “Processing” and 0.5 m3/h in “Ready for operation”. Further the machine tool consumes 0.001 kg/h lubrication oil for lubrication. The impact of these inputs also flows into the overall impact over the life cycle.


M.4.a.xxi. Life Cycle Stage 4: Use

To derive improvement measures, the electrical power consumption has to be split up into the different sub-systems.


M.4.a.xxii. Life Cycle stage 5: End-of-Life

As described in the End-of-Life scenario, the metal parts and electronic components of the machine tool are recycled at the end of its life, the plastics will get incinerated, and some inert materials may be disposed on a landfill.


M.4.a.xxiii. Life Cycle stage 5: End-of-Life

We note the parts that are recycled, incinerated, ore disposed of in a landfill. Commonly, the majority of machine tool components are recycled. For each part, we can define an own end of life scenario.

Case Study Machine toolM.4.b. What happens with the data entered for the Machine tool

The data that is entered is multiplied with the corresponding Datasets from the Life Cycle Inventory Database to give the Environmental impact for this specific part of the life cycle. The total impacts can be summed over the life cycle stages to give the overall environmental load of the product.In the case of the machine tool, the Cumulative Energy Demand (CED) is used to describe the environmental load.

M.5. Case study: Machine tools (M)M.5. Review the results

Substeps:a. Understand the first result & the available impact categoriesb. Identify major environmental hotspots and the robustness of the underl

ying datac. Collect and enter additional data where necessary

Case Study Machine toolM.5.a. Understand the first result & the available impact categories for the Machine tool

For the machine tools, the KEPI of Cumulative Energy Demand (CED) is used to describe the environmental impact of the product. Having entered much more detailed data, we have a greater depth and level of detail in the results, compared to the rough assessment.

Case study navigation

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Case Study Machine toolM.5.b. Identify major environmental hotspots and the robustness of the underlying data for the Machine toolThe major environmental hotspot is the electricity consumption in the Use stage, followed by the raw materials used in the Materials stage. The data used to calculate the environmental impacts of these stages is robust. The result can therefore be considered as robust.

Case Study Machine toolM.5.c. Collect and enter additional data where necessary for the Machine tool

The below table describes the improved data. In contrast to the Rough assessment, it was necessary to collect additional data for the Use stage.


Data source

Bill of materials, Designers, Engineering department

Electricity bill, Production facility manager

Marketing and Sales department

Measurement by Engineering department (preferably following ISO 14955)

Designers, Engineering department

Waste management system, Production facility manager

Logistics department

Data quality

(DQI)

Robust Indicative Indicative Robust Illustrative

M.6. Case study: Machine tools (M)M.6. Review the results

Substeps:a. Draw conclusions from the resultb. Derive appropriate improvement measuresc. Prepare the result for distribution / communication

Case Study Machine toolM.6.a.i. Draw conclusions from the result for the Machine tool

It can clearly be seen that the use stage accounts over 96% of the impact over the lifecycle of the machine tool.


M.6.a.ii. Detailed results –Use stageThe first figure shows the breakdown of the CED in the Use stage. It can clearly be seen that most of the impact is in the state “Processing”. Followed by a figure showing the breakdown of energy consumption in the various subsystems. The three components with the greatest impact are the Lubrication Pump, the E/R module supply, and the Fluid system. Appropriate improvements can be found in the next step.


M.6.a.iii. Detailed results –Use stage

This figure shows the three use scenarios. You can clearly see the difference between a one shift regime, a two shift regime, and a three shift regime.


Improvement Guidelines

Depending on the results, we find improvement guidelines to the different subsystems.The suggested improvement measures are in line with ISO14955. Improvement measures should first focus on the most relevant components in the most relevant life cycle stages.

M.6.b.i. Derive appropriate improvement measures from the environmental assessment of the Machine tool

Case Study Machine toolM.6.b.ii. Derive appropriate improvement measures from the environmental assessment of the Machine toolAs an example, the following three General improvement options were identified• Minimisation of moved massesMoved masses have to be accelerated and the energy required for acceleration is depending on the mass (W = 1/2*m*v²). Even if some part of the energy is recovered during braking, this recovery is with an efficiency factor below 1. The best way reducing energy needed for acceleration is mass reduction.

• Reduction of frictionAvoidance of friction means less mechanical wear, higher quality and also should lead to energy reduction; various types of bearing possible (rolling bearing, sliding bearing, hydrostatic bearing, magnet bearing); ecological aspect has to be considered by choose of bearing as well. Reduction of speed dependent friction must be optimized in respect to the characteristic of choosen drive technology.

• Optimization of the overall machine designCheck, if the machine tool has been designed according to customer requirements; operational range been specified close to optimal working point; avoiding adding up spare capacities (over sizing)

Case Study Machine toolM.6.c. Prepare the result for distribution / communicationof the environmental assessment of the Machine toolYou can export the findings into Excel or use the provided PDF report for

internal and external communication.

M. Case study: Machine tools (M)

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