Adjacency Matrix Calculator for Construction Networks

Scenario: Five work zones with handoffs between them.

Paste these pairs into the edge list box to reproduce the sample.

• Adjacency matrix: A[i,j] = weight of link i → j, otherwise 0.
• Undirected links: A[i,j] = A[j,i] for every connection.
• Out degree: number of nonzero entries in row i.
• In degree: number of nonzero entries in column i.
• Strength: sum of weights in the row or column.
• Density: edges ÷ possible links (excluding self links).

1. Choose the number of nodes for zones or crews.
2. Enter labels to match your site layout and workflow.
3. Paste one connection per line in the edge list.
4. Enable directed mode for one-way task handoffs.
5. Enable weighted mode to represent volume or priority.
6. Submit to view the matrix and summary metrics above.
7. Download CSV or PDF to share results with the team.

Adjacency matrices help map how crews, equipment, and materials move between zones. High density can indicate congestion risk, while low density can reveal missing handoffs. Directed links fit sequenced work, such as inspections after placement. Weighted links approximate repeated trips, volume, or priority. Use degree to spot high-traffic nodes that may need wider access, clearer signage, or staggered timing.

1) Why adjacency matters on site

Construction work depends on handoffs: deliveries reach laydown areas, materials move to prep stations, and crews follow sequences. An adjacency matrix turns those relationships into a structured table so planners can compare options quickly. With 2–20 nodes, you can model a small renovation or a multi-zone project floor.

2) Defining nodes and links

Nodes can represent zones (Gate, Storage, Mix, Pour, Finish), trades, equipment hubs, or inspection checkpoints. Links describe movement or dependency. Use directed links for one-way sequences, such as “Pour → Finish,” and undirected links for shared access, such as a corridor used both ways.

3) Using weights as operational data

Weighted links let you encode volume, frequency, or priority. For example, a weight of 6 may represent six forklift trips per hour, while 2 may represent occasional access. When weight is omitted, the default weight provides consistent baseline scoring for rapid scenario setup.

4) Reading the matrix for bottlenecks

Each row shows what a node sends out; each column shows what it receives. Large values concentrated in one row can indicate a staging hotspot. Large values concentrated in one column can indicate a downstream dependency that may require buffer space, extended hours, or alternate routing.

5) Degree and strength for prioritization

Degree counts how many distinct connections exist, while strength sums the total flow. A node with high degree but low strength can be a coordination hub. A node with low degree but high strength can be a heavy-flow corridor that deserves wider access and clearer controls.

6) Density as a complexity indicator

Density compares actual links to the number of possible links. Low density often reflects a linear workflow that is easier to schedule. Higher density can reflect parallel trades, shared resources, or chaotic routing. Use density trends to justify traffic control plans and phased zoning.

7) Connectivity checks for isolation risk

The weak connectivity check treats the network as undirected to confirm every node is reachable in practice. If the network is not connected, a zone may be isolated by access restrictions, sequencing gaps, or missing logistics. Update the edge list to validate a revised site plan.

8) Reporting and collaboration

Exporting CSV supports spreadsheet review, while PDF supports quick briefings and daily huddles. Keep labels consistent with drawings and method statements so stakeholders interpret results correctly. Store scenarios as separate runs to compare alternative routes, shift plans, and staging layouts over time.

1) What should I use as a node?
Use zones, trades, equipment hubs, or inspection points. Choose labels that match drawings and daily language so the matrix stays practical for coordination.

2) When should I enable directed mode?
Use directed mode for ordered workflows, like “Formwork → Rebar → Pour → Finish,” or when movement is allowed one way due to safety or access control.

3) How do weights help construction planning?
Weights approximate frequency, volume, or priority. They help distinguish a heavy logistics route from a minor interaction, improving staging, access width, and timing decisions.

4) Why does my matrix show symmetry as “No”?
Symmetry means A[i,j] equals A[j,i]. If you used directed links or entered different weights in opposite directions, the matrix will not be symmetric.

5) What does density tell me?
Density measures how many links exist compared to the maximum possible. Higher density suggests more coordination and potential congestion, while lower density suggests simpler, phased movement.

6) What if I see “not connected”?
It means at least one node cannot be reached when considering links in either direction. Add missing handoffs or access routes to validate the feasibility of the plan.

7) Can I model repeated edges between the same nodes?
Yes. If you enter the same pair multiple times, the calculator sums the weights. This can represent multiple routes, repeated trips, or combined flows.