bom

A few helpers to work with data representing bill of materials (bom).

Developer Guide

Installation

Install latest from the GitHub repository:

$ pip install git+https://github.com/janhesse53/bom.git

Documentation

Documentation can be found hosted on this GitHub repository’s pages.

How to use

df, df_attributes = get_sample_data()

Build the complete graph from df (optionally merging df_attributes):

G = build_complete_graph(df, df_attributes)

# Let's confirm the number of nodes (20 unique items)
print("Number of nodes:", G.number_of_nodes())
print("Number of edges:", G.number_of_edges())

Number of nodes: 20
Number of edges: 21

Often, we only want to visualize one product (like PUMP_RV2) and its sub-components:

sub_g = select_subg_by_root(G, 'PUMP_RV2')
sub_g.nodes()

NodeView(('MOTOR_A1', 'CASE_STD1', 'PUMP_RV2', 'BEARING_01', 'VANE_002', 'VANE_ASM2'))

sub_g = add_levels(sub_g)
[(n[0],n[1]['level']) for n in sub_g.nodes(data=True)]

[('MOTOR_A1', 1),
 ('CASE_STD1', 1),
 ('PUMP_RV2', 0),
 ('BEARING_01', 2),
 ('VANE_002', 2),
 ('VANE_ASM2', 1)]

plot_graph(sub_g, layout='multipartite', figsize=(5,4), font_size=8)

Graph Querying

With the complete graph, we can answer many questions:

Which products contain a certain part?

get_all_predecessors(G, 'BEARING_01')

['VANE_ASM1', 'VANE_ASM2', 'PUMP_RV1', 'PUMP_RV2']

All sub-components of a certain product?

get_all_successors(G, 'PUMP_CL1')

['MOTOR_A1', 'CASE_CL1', 'CLAW_ASM1', 'CLAW_001', 'BEARING_02']

Edge attributes (like quantity):

for (u,v,d) in G.edges(data=True):
  if 'quantity' in d and d['quantity'] > 1:
      print(u, '-->', v, '[qty=', d['quantity'], ']')

VANE_ASM1 --> VANE_001 [qty= 6 ]
VANE_ASM1 --> BEARING_01 [qty= 2 ]
VANE_ASM2 --> VANE_002 [qty= 6 ]
VANE_ASM2 --> BEARING_01 [qty= 2 ]
SCREW_ASM1 --> SCREW_001 [qty= 2 ]
SCREW_ASM1 --> BEARING_02 [qty= 4 ]
CLAW_ASM1 --> CLAW_001 [qty= 2 ]
CLAW_ASM1 --> BEARING_02 [qty= 4 ]

Node attributes (like component_type, cost):

# Example: Print the cost of each node if it exists
for n, attrs in G.nodes(data=True):
  if 'cost' in attrs:
      print(n, 'cost=', attrs['cost'])

PUMP_RV1 cost= 2500
MOTOR_A1 cost= 800
CASE_STD1 cost= 400
VANE_ASM1 cost= 300
OIL_SYSTEM1 cost= 150
VANE_001 cost= 50
BEARING_01 cost= 30
PUMP_RV2 cost= 2300
VANE_ASM2 cost= 280
VANE_002 cost= 65
PUMP_SC1 cost= 3000
MOTOR_B1 cost= 1000
CASE_SC1 cost= 600
SCREW_ASM1 cost= 450
SCREW_001 cost= 150
BEARING_02 cost= 45
PUMP_CL1 cost= 2800
CASE_CL1 cost= 450
CLAW_ASM1 cost= 400
CLAW_001 cost= 140