Removable media storage units

1. Scope and Applicability

This PCR covers computing peripherals that read or write physically removable media: optical-disc drives, removable magnetic-disk drives, tape drives and flash-card readers. The device, rather than the removable medium, is the product. Fixed-media drives, flash-memory cards, standalone audiovisual players and host computers are excluded. The classification title is verified in un-cpc-3-0-structure-2025; the device/media distinction follows the explanatory note in un-cpc-2-1-removable-storage.

The foreground package covers receipt of purchased components through assembly, functional testing and packaging at the factory gate. Component manufacture is represented by upstream datasets, including semiconductor fabrication and board population; it is not treated as burden-free. The inventory below is a compact component-assembly route. Integrated component manufacturing requires additional measured unit processes. Do not apply the optical component quantities to tape drives or card readers. The electronics life-cycle decomposition in epa-sustainable-electronics-roadmap supports separating component production, assembly and rejects; it provides no unit-specific consumption factors.

2. Product Category Identity

Field	Value
canonical_pcr_id	pcr.metal-products-machinery-and-equipment.office-accounting-and-computing-machinery.removable-media-storage-units
classification_refs	CPC 3.0: 45272; classification identity only
covered_products	Removable optical-disc drives, magnetic-disk drives, magnetic-tape drives and flash-card readers for computing
excluded_products	Fixed-media drives; flash cards and recording media; host computers; standalone audiovisual players
representative_product	Factory-tested optical-disc drive supplied without removable media
production_route	Purchased populated controller board and finished mechanical components; assembly; functional testing; packaging
market_state	New, tested device at factory gate; packaging recorded separately from net device mass

3. Reference Flow

Field	Value
What	Read or write a declared removable-media format for a host computer
How much	1 kg net finished devices of one declared model; also report device count and kg/device
How well	Declare interface, supported media, read/write capability, throughput and acceptance-test criteria
How long or cycle	One production batch through final acceptance; service lifetime is not normalized into this production-only package
reference_flow_link	reference_product; production declared unit, not a claim of equal lifetime storage service

Field	Value
Reference amount	1
Reference product flow	Removable media storage units d0af9a31-3017-4ab7-a6e4-172f40cd7bb1
Reference flow property	Mass 93a60a56-a3c8-11da-a746-0800200b9a66
Reference unit group	Units of mass 93a60a57-a4c8-11da-a746-0800200c9a66
Reference unit	kg
Required qualifiers	device type; model; supported removable-media format; interface; read/write capability; throughput and test method; net kg/device; accessories included; packaging configuration; factory; country; production period; purchased-component boundary; acceptance yield

Declare all required qualifiers in the foreground package. A comparison based on storage service additionally requires workload, media consumption, operating modes, reliability and service duration; this production declared unit alone cannot establish functional equivalence.

4. Measurement and Unit Rules

rule_id	Applies to	Required property	Required unit	Rule
net_mass	reference product	Mass	kg	Weigh accepted devices without packaging or removable media; convert count using measured model-specific kg/device. Never convert storage capacity to device mass.
energy	electricity	Net calorific value	MJ	Preserve metered energy; convert kWh to MJ by multiplying by 3.6. Allocate meter coverage once; test electricity must not be counted again in assembly electricity.
component_mass	components	Mass	kg	Use received component mass and reconcile installed mass, rejects, returns and stock changes. A populated board dataset includes its mounted components; do not count them twice.

5. System Boundary

rule_id	applies_to	rule	source_ids
boundary_production	foreground	Include component receipt, assembly, testing, rework, packing and associated energy and production rejects. Record purchased components with upstream production links.	epa-sustainable-electronics-roadmap
boundary_disclosure	data package	Disclose the gate-to-gate foreground and upstream coverage separately; include inbound transport in linked supply datasets or separately measured transport processes, once only. Excluded downstream use and disposal mean this is not a complete product life-cycle footprint.	ghg-protocol-product-standard
boundary_completeness	site inventory	Reconcile the actual bill of materials and site process register with the listed exchanges. Add separate atomic rows for any additional component, chemical, fuel, water, waste or direct emission actually crossing the boundary; absence needs site evidence, not an assumed zero.	ghg-protocol-product-standard

Boundary Abstraction

Field	Value
declared_starting_condition	Purchased finished components and populated boards received for device assembly
starting_condition_role	Foreground entry gate; not a zero-burden cut-off
product_classification_scope	Removable-media computing storage devices, excluding the removable media
recursive_input_rule	Purchased complete drives used inside an enclosure are recorded once as a same-category input with supplier boundary and upstream dataset; never recursively recreate the same assembly or omit its burdens.
upstream_dataset_requirement	Link each purchased component to a geographically and technologically suitable production dataset; state missing links and avoid overlapping component and raw-material inventories.
disclosure	Starting state; component make/buy boundary; transport coverage; production period; included accessories; losses; exclusions; downstream stages not represented

6. Process Inventory Structure

Process Map

process_id	process_name	inclusion	inclusion_condition	role	quantitative_reference
assembly	Component assembly, functional testing and packing	required	All devices; component cards are conditional on the bill of materials	foreground production	1 kg accepted net devices

One batch-level process encompasses assembly, test and packing because the reference output and loss reconciliation share one production ledger. Keep operation-level electricity and test-time records within the collection protocol. Internal movements and rework are not fictitious purchased intermediate flows.

Process: Component assembly, functional testing and packing (assembly)

Inputs

Product flows

Populated storage-drive controller board (controller_board)

When the specified controller board is purchased for the device.

• Selected flow: Populated storage-drive controller board
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg; unit group 93a60a57-a4c8-11da-a746-0800200c9a66
• Inclusion condition: When the specified controller board is purchased for the device.
• Amount rule: Aggregate matched-period net exchange from cp_batch and divide by accepted net output mass using normalize_batch.
• Value mode: Calculated value (calculated_value)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted net devices
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_batch

Finished steel drive housing (steel_housing)

When the model has a purchased steel housing; do not apply to a plastic enclosure.

• Selected flow: Finished steel drive housing
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg; unit group 93a60a57-a4c8-11da-a746-0800200c9a66
• Inclusion condition: When the model has a purchased steel housing; do not apply to a plastic enclosure.
• Amount rule: Aggregate matched-period net exchange from cp_batch and divide by accepted net output mass using normalize_batch.
• Value mode: Calculated value (calculated_value)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted net devices
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_batch

Optical-disc drive spindle motor (motor)

When an optical-drive spindle motor is separately purchased; exclude if already included in a purchased mechanism dataset.

• Selected flow: Optical-disc drive spindle motor
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg; unit group 93a60a57-a4c8-11da-a746-0800200c9a66
• Inclusion condition: When an optical-drive spindle motor is separately purchased; exclude if already included in a purchased mechanism dataset.
• Amount rule: Aggregate matched-period net exchange from cp_batch and divide by accepted net output mass using normalize_batch.
• Value mode: Calculated value (calculated_value)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted net devices
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_batch

Optical disc drive laser pickup unit (laser_pickup)

When an optical laser pickup is separately purchased; include the module, not its constituent parts again.

• Selected flow: Optical disc drive laser pickup unit 634db7bf-732f-47ee-9546-ac7f2026a939
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg; unit group 93a60a57-a4c8-11da-a746-0800200c9a66
• Inclusion condition: When an optical laser pickup is separately purchased; include the module, not its constituent parts again.
• Amount rule: Aggregate matched-period net exchange from cp_batch and divide by accepted net output mass using normalize_batch.
• Value mode: Calculated value (calculated_value)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted net devices
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_batch

Magnetic tape-drive read/write head (tape_head)

When a magnetic tape-drive head is separately purchased.

• Selected flow: Magnetic tape-drive read/write head
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg; unit group 93a60a57-a4c8-11da-a746-0800200c9a66
• Inclusion condition: When a magnetic tape-drive head is separately purchased.
• Amount rule: Aggregate matched-period net exchange from cp_batch and divide by accepted net output mass using normalize_batch.
• Value mode: Calculated value (calculated_value)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted net devices
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_batch

Flash-memory card socket (card_connector)

When a flash-card socket is separately purchased; exclude if already mounted on the purchased populated board.

• Selected flow: Flash-memory card socket
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg; unit group 93a60a57-a4c8-11da-a746-0800200c9a66
• Inclusion condition: When a flash-card socket is separately purchased; exclude if already mounted on the purchased populated board.
• Amount rule: Aggregate matched-period net exchange from cp_batch and divide by accepted net output mass using normalize_batch.
• Value mode: Calculated value (calculated_value)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted net devices
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_batch

Steel screw (screws)

When steel screws are issued for assembly; record actual grade and coating.

• Selected flow: Steel screw 895204f6-6425-4814-afc5-cb97e530e892
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg; unit group 93a60a57-a4c8-11da-a746-0800200c9a66
• Inclusion condition: When steel screws are issued for assembly; record actual grade and coating.
• Amount rule: Aggregate matched-period net exchange from cp_batch and divide by accepted net output mass using normalize_batch.
• Value mode: Calculated value (calculated_value)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted net devices
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_batch

corrugated board boxes (box)

When a corrugated-board shipping box is used; record mass per package and devices per box.

• Selected flow: corrugated board boxes 4f197bec-7b3b-11dd-ad8b-0800200c9a66
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg; unit group 93a60a57-a4c8-11da-a746-0800200c9a66
• Inclusion condition: When a corrugated-board shipping box is used; record mass per package and devices per box.
• Amount rule: Aggregate matched-period net exchange from cp_batch and divide by accepted net output mass using normalize_batch.
• Value mode: Calculated value (calculated_value)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted net devices
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_batch

Electricity (electricity)

Purchased electricity for assembly, testing and packing, including attributable shared services; retain operation submeter records.

• Selected flow: Electricity 890a70b7-b677-4e2a-8a1b-7d017e0a10ae
• Flow property / unit: Net calorific value 93a60a56-a3c8-11da-a746-0800200c9a66 / MJ; unit group 93a60a57-a3c8-11da-a746-0800200c9a66
• Inclusion condition: Purchased electricity for assembly, testing and packing, including attributable shared services; retain operation submeter records.
• Amount rule: Aggregate matched-period net exchange from cp_batch and divide by accepted net output mass using normalize_batch.
• Value mode: Calculated value (calculated_value)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted net devices
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_batch

Outputs

Product flows

Removable media storage units (reference_product)

Accepted device output only; packaging mass is excluded from this reference output.

• Selected flow: Removable media storage units d0af9a31-3017-4ab7-a6e4-172f40cd7bb1
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg; unit group 93a60a57-a4c8-11da-a746-0800200c9a66
• Inclusion condition: Accepted device output only; packaging mass is excluded from this reference output.
• Amount rule: Calculate accepted net mass from accepted count and measured kg/device, then normalize to 1 kg.
• Value mode: Calculated value (calculated_value)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted net devices
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_batch

Waste flows

Discarded optical-disc drive (reject)

When a failed optical drive is discarded as a whole device; record waste destination. Rework is not waste until discarded.

• Selected flow: Discarded optical-disc drive
• Flow property / unit: Mass 93a60a56-a3c8-11da-a746-0800200b9a66 / kg; unit group 93a60a57-a4c8-11da-a746-0800200c9a66
• Inclusion condition: When a failed optical drive is discarded as a whole device; record waste destination. Rework is not waste until discarded.
• Amount rule: Aggregate matched-period net exchange from cp_batch and divide by accepted net output mass using normalize_batch.
• Value mode: Calculated value (calculated_value)
• Specificity: Site-specific (site_specific)
• Normalization basis: per 1 kg accepted net devices
• Basis kind: Reference flow (reference_flow)
• Evidence kind: Calculated from collection (calculated_from_collection)
• Collection protocol: cp_batch

7. Allocation and Co-product Handling

rule_id	applies_to	rule	source_ids
allocation_subdivision	shared production	Use product-line and operation metering before allocating shared burdens. Where subdivision is infeasible use a demonstrated physical driver such as occupied equipment time; document why it reflects resource use and test sensitivity.	ghg-protocol-product-standard
allocation_rejects	yield and recycling	Retain failed-test and rework burdens in accepted output. Track rejects separately and do not treat them as saleable reference product. Declare a consistent recycling allocation method; do not deduct an assumed avoided virgin-material credit.	ghg-protocol-product-standard

8. Foreground Data Collection, Calculation, and Quality Rules

Data Collection Protocols

protocol_id	process_id	flow_role	record_type	raw_fields	collection_method	unit	frequency	temporal_coverage	site_scope	aggregation_rule	quality_evidence
cp_batch	assembly	Components, energy, packaging, accepted product and rejects	batch ledger and meters	model; lot; component identity; issued mass; returns; opening and closing stock; accepted count; net device mass; reject mass; meter readings; run and test hours; destinations	Reconcile BOM, purchasing and production ledgers with calibrated weighing, submetering, acceptance tests and waste transfer records	kg; count; MJ; h	each batch and meter interval	Full declared production period including shutdowns and rework	Declared factory and shared services	Aggregate net exchanges over the same period; allocate shared service once; divide by accepted net mass	Calibration; supplier specifications; invoices; test logs; waste receipts; allocation reconciliation

Calculation Rules

rule_id	Applies to	Formula or rule	Inputs	Output	source_ids
normalize_batch	all exchanges	q_i = allocated net batch exchange i / accepted net batch mass; reference output = 1 kg	cp_batch quantities and accepted count times measured kg/device	kg or MJ per kg reference product
net_issues	purchased components	Net issue = opening stock + receipts - closing stock - supplier returns; reconcile against installed components and measured rejects	cp_batch mass ledger	Component input mass
meter_partition	electricity	Sum operation meters; allocate unmetered shared services using justified occupied equipment time; reconcile total to the site bill	cp_batch energy and runtime	Purchased electricity attributable to this batch

These are foreground bookkeeping identities, not literature-derived yield or consumption estimates.

Data Quality Requirements

requirement_id	Applies to	Requirement	Evidence
dq_identity	device and components	Verify removable-media function and actual BOM; record purchased board population and mechanical-module scope	Supplier drawings and acceptance specifications
dq_period	all records	Use one matched production period and report missing periods, meter allocation, representativeness and uncertainty	cp_batch; ghg-protocol-product-standard chapter 8
dq_coverage	material and waste balances	Investigate discrepancy between issued mass, device output, scrap, returns and stock movement using measurement uncertainty; no unsupported tolerance is prescribed	Signed mass reconciliation and waste receipts
dq_ranges	foreground amounts	Collect actual amounts; do not replace absent measurements with a generic optical-drive, tape-drive or reader benchmark	cp_batch

9. Validation Rules

rule_id	applies_to	rule	source_ids
validate_identity	reference product	Require all qualifiers, net device mass and acceptance records. Reject a fixed-media drive or a removable medium presented as the reference device.	un-cpc-2-1-removable-storage
validate_inventory	quantities	Verify each actual exchange is atomic, normalized to accepted output, supported by cp_batch, and assigned once; reconcile BOM, electricity and waste totals. Missing data are unresolved, not zero.	ghg-protocol-product-standard
validate_boundary	downstream claims	Require explicit upstream links and disclosure of unmodelled stages; prohibit lifetime service comparisons from this production-only package without an additional use and end-of-life model.	ghg-protocol-product-standard

10. Published Dataset Profile

Field	Value
dataset_role	Foreground production dataset for a specified removable-media device model
downstream_use	secondary_dataset; background_dataset
allowed_use	Production input to host-computer or peripheral-device life-cycle models with compatible boundaries
excluded_use	Removable-media manufacture; fixed-media drive production; generic lifetime storage-service comparison; claim of a full life-cycle footprint
required_metadata	Model; device technology; site; country; period; net mass; count; acceptance criteria; BOM scope; upstream links; transport treatment; allocation
required_quality_disclosure	Measurement coverage; supplier-data gaps; unresolved flow identities; missing upstream datasets; uncertainty; exclusions
update_trigger	BOM, manufacturing route, supplier technology, test protocol, site energy or reference-product specification changes

11. Data Sources

Source id	Type	Reference	Used for
un-cpc-3-0-structure-2025	official_guidance	UNSD, CPC 3.0 structure, 30 June 2025; https://unstats.un.org/unsd/classifications/Econ/Download/In%20Text/CPC_Ver_3.0_Structure_30Jun2025.csv ; retrieved 2026-09-09	Exact classification title; independence_key: un-cpc-3-0-structure-2025
un-cpc-2-1-removable-storage	official_guidance	UNSD, CPC 2.1 explanatory note 45272; https://unstats.un.org/unsd/classifications/Econ/Detail/EN/1074/45272 ; retrieved 2026-09-09	Prior-version device/media boundary explanation, not asserted as CPC 3.0 explanatory text; independence_key: un-cpc-2-1
epa-sustainable-electronics-roadmap	official_guidance	US EPA, E. Sahle-Demessie, Sustainable Electronics Roadmap, slides 7, 11 and 16; https://www.epa.gov/sites/default/files/2014-05/documents/roadmap.pdf ; retrieved 2026-09-09	Electronics components/assembly/reject decomposition and measured energy need; no amount factors; independence_key: epa-sustainable-electronics-roadmap
ghg-protocol-product-standard	standard	WRI/WBCSD, Product Life Cycle Accounting and Reporting Standard, 2011, chapters 7–9; https://ghgprotocol.org/sites/default/files/ghgp/standards/Product-Life-Cycle-Accounting-Reporting-Standard_041613.pdf ; retrieved 2026-09-09	Boundary disclosure, primary records and allocation hierarchy adapted to a production dataset; not a claim of full standard conformance; independence_key: ghg-protocol-product-standard-2011