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Buzen's Algorithm

A station-by-station dynamic program for the normalization constant of a finite-population, closed product-form queueing network.

Version
v1 · 2026-10-03 · History
Domain-specific #
13035
Domain group
Applied Sciences & Engineering
Origin domain
Computer Science & Software Engineering
Subdomain
Queueing Theory → Computer Science & Software Engineering
Aliases
Buzen Algorithm, Buzen Convolution Algorithm

Core Idea

Buzen's algorithm computes the normalizing constant for a finite-population closed queueing network whose stationary weights have product form. It builds reusable partial normalizers across stations and population counts instead of repeatedly enumerating complete occupancy states. The compact two-term recurrence is a geometric-station-factor special case, not a formula for all product-form networks.[ref-a758285a610c][ref-f0a8e8804b71]

Scope of Application

For closed computer-device models with homogeneous service factors \(Y_m^q\), the update is \(g_m(n)=g_{m-1}(n)+Y_mg_m(n-1)\). Fixed-pallet manufacturing models can also require a product-form normalizer, but multiserver occupancy factors may require the fuller convolution \(g_m(n)=\sum_{q=0}^{n}f_m(q)g_{m-1}(n-q)\). Valid product-form weights must be established before either computation is interpreted.[ref-f0a8e8804b71][ref-a97b5b11a61d]

Clarity

Here \(g_m(n)\) sums weights for \(n\) customers over the first \(m\) stations; \(G(N)=g_M(N)\) is the full normalizer. The general update groups states by the \(q\) customers at the newly included station. Geometric factors permit the two-term shortcut by algebraic reindexing. Throughput and utilization are derived with additional formulas, not returned directly by \(G(N)\).[ref-f0a8e8804b71][ref-a97b5b11a61d]

Manages Complexity

Reusing partial sums reduces the geometric-factor case to a table with work proportional to the number of population–station entries. More complex factors entail longer convolutions unless other structure is exploited. Speed does not compensate for a wrong queueing model or an inapplicable short recurrence.[ref-f0a8e8804b71][ref-296b5fd6fe15]

Abstract Reasoning

The algorithm's state has two coordinates: stations included and circulating population represented. Each station update sums over possible local occupancy while retaining the previous aggregate. Thus it separates the stationary-model question—whether the weights factor—from the computational question—how to sum their normalization constant.[ref-f0a8e8804b71][ref-a97b5b11a61d]

Knowledge Transfer

A computer network with fixed jobs and a manufacturing network with fixed pallets share the closed-population, station-factor and partial-normalizer pattern. The former's geometric factors admit the two-term update; the latter's piecewise multiserver factors may not. The transferable method is station-by-station aggregation, not indiscriminate reuse of one special formula.[ref-f0a8e8804b71][ref-a97b5b11a61d]

[^ref-a758285a610c]: Jeffrey P. Buzen, “Computational Algorithms for Closed Queueing Networks with Exponential Servers,” Communications of the ACM 16(9), 527–531 (1973), public abstract and metadata. [^ref-f0a8e8804b71]: Peter J. Denning and Jeffrey P. Buzen, “The Operational Analysis of Queueing Network Models,” ACM Computing Surveys 10(3), 225–261 (1978), §7, Figure 16. [^ref-a97b5b11a61d]: Xuebin Li, Hyeon-Il Kim and Dong-Ho Lee, “Capacity Scalability Planning Algorithms for Job-shop-type Reconfigurable Manufacturing Systems with Dynamic Demands,” Journal of the Korean Institute of Industrial Engineers 50(3), 157–172 (2024), §2.2. [^ref-296b5fd6fe15]: National Bureau of Standards, An Analytic Study of a Shared Device Among Independent Computing Systems, Special Publication 500-69 (1980), historical review.

Relationships to Other Abstractions

Local relationship map for Buzen's AlgorithmParents appear above the current abstraction, mutual partners to the right, and children below. Node labels state whether each abstraction is prime or domain-specific; colors identify relation types.Buzen's AlgorithmDOMAINPrime abstraction: Queueing — presupposesQueueingPRIME

Current abstraction Buzen's Algorithm Domain-specific

Parents (1) — more general patterns this builds on

  • Buzen's Algorithm presupposes Queueing Prime

    The normalization algorithm presupposes a closed network of waiting and service stations; it is not itself a queue.

Hierarchy paths (2) — routes to 2 parentless roots

Neighborhood in Abstraction Space

Buzen's Algorithm sits in a sparse region of the domain-specific corpus (73rd percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.

Family — Supply Chain & Inventory Management (28 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-10-08