Procurement Models

Material

Catalog of materials used in EV charger installations.

Field	Type	Constraints	Description
id	UUIDField	PK, default=uuid4	Primary key
name	CharField(200)	not null	Material name
sku	CharField(50)	unique	Stock keeping unit code
category	CharField(50)	choices: charger, cable, mounting, electrical, misc	Material category
unit	CharField(20)	choices: piece, meter, kg, set	Unit of measurement
description	TextField	blank	Detailed description

MaterialStock

Inventory levels per material per zone.

Field	Type	Constraints	Description
id	UUIDField	PK, default=uuid4	Primary key
material	ForeignKey(Material)	not null, on_delete=CASCADE	Material reference
zone	ForeignKey(Zone)	not null, on_delete=PROTECT	Stock location zone
quantity_available	IntegerField	not null, >=0	Current available stock
reorder_level	IntegerField	default=5	Threshold for reorder alerts
updated_at	DateTimeField	auto_now	Last stock update

Unique constraint: (material, zone)

MaterialAllocation

Records material reserved or dispatched for a specific installation.

Field	Type	Constraints	Description
id	UUIDField	PK, default=uuid4	Primary key
installation	ForeignKey(Installation)	not null, on_delete=CASCADE	Target installation
material	ForeignKey(Material)	not null, on_delete=PROTECT	Allocated material
quantity	IntegerField	not null, >0	Quantity allocated
allocated_by	ForeignKey(User)	not null, on_delete=PROTECT	Procurement staff who allocated
status	CharField(20)	choices: allocated, dispatched, delivered, returned	Allocation lifecycle state
allocated_at	DateTimeField	auto_now_add	Allocation timestamp

ProcurementRequest

Request to procure materials locally when zone stock is insufficient.

Field	Type	Constraints	Description
id	UUIDField	PK, default=uuid4	Primary key
installation	ForeignKey(Installation)	not null, on_delete=CASCADE	For which installation
material	ForeignKey(Material)	not null, on_delete=PROTECT	What material is needed
quantity	IntegerField	not null, >0	Quantity needed
vendor	ForeignKey(Vendor)	nullable, on_delete=SET_NULL	Local vendor if identified
status	CharField(20)	choices: requested, approved, ordered, received, cancelled	Request lifecycle state
estimated_cost	DecimalField(10,2)	nullable	Expected cost before ordering
actual_cost	DecimalField(10,2)	nullable	Final cost after receiving
requested_by	ForeignKey(User)	not null, on_delete=PROTECT	Who created the request
created_at	DateTimeField	auto_now_add	Request creation timestamp

Vendor

Local suppliers for material procurement.

Field	Type	Constraints	Description
id	UUIDField	PK, default=uuid4	Primary key
name	CharField(200)	not null	Vendor business name
phone	CharField(15)	not null	Contact number
zone	ForeignKey(Zone)	not null, on_delete=PROTECT	Vendor’s operating zone
upi_id	CharField(100)	nullable	UPI/QR payment identifier
bank_account	CharField(20)	nullable	Bank account number
bank_ifsc	CharField(15)	nullable	Bank IFSC code
is_active	BooleanField	default=True	Whether vendor is active

Note: At least one payment method (upi_id or bank_account + bank_ifsc) should be provided, enforced at the application level.