### Abstract

Practical optimization/approximation algorithms are described for scheduling a set of partially ordered computational tasks onto a multiprocessor system so that the schedule length will be minimized. Since this problem belongs to the class of 'strong' NP-hard problems, it is not possible to construct pseudopolynomial time optimization algorithms or fully polynomial time approximation schemes unless P equals NP. A heuristic algorithm named CP/MISF (critical path/most immediate successors first) and an optimization/approximation algorithm named DF/IHS (depth-first/implicit heuristic search) are proposed. DF/IHS is an excellent scheduling method which can reduce markedly space complexity and average computation time by combining the branch-and-bound method with CP/MISF; it allows us to solve very large scale problems with a few hundred tasks. Numerical examples are included to demonstrate the effectiveness of the proposed algorithms.

Original language | English |
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Pages (from-to) | 1023-1029 |

Number of pages | 7 |

Journal | IEEE Transactions on Computers |

Volume | C-33 |

Issue number | 11 |

Publication status | Published - 1984 Nov |

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### ASJC Scopus subject areas

- Hardware and Architecture
- Electrical and Electronic Engineering

### Cite this

*IEEE Transactions on Computers*,

*C-33*(11), 1023-1029.

**PRACTICAL MULTIPROCESSOR SCHEDULING ALGORITHMS FOR EFFICIENT PARALLEL PROCESSING.** / Kasahara, Hironori; Narita, Seinosuke.

Research output: Contribution to journal › Article

*IEEE Transactions on Computers*, vol. C-33, no. 11, pp. 1023-1029.

}

TY - JOUR

T1 - PRACTICAL MULTIPROCESSOR SCHEDULING ALGORITHMS FOR EFFICIENT PARALLEL PROCESSING.

AU - Kasahara, Hironori

AU - Narita, Seinosuke

PY - 1984/11

Y1 - 1984/11

N2 - Practical optimization/approximation algorithms are described for scheduling a set of partially ordered computational tasks onto a multiprocessor system so that the schedule length will be minimized. Since this problem belongs to the class of 'strong' NP-hard problems, it is not possible to construct pseudopolynomial time optimization algorithms or fully polynomial time approximation schemes unless P equals NP. A heuristic algorithm named CP/MISF (critical path/most immediate successors first) and an optimization/approximation algorithm named DF/IHS (depth-first/implicit heuristic search) are proposed. DF/IHS is an excellent scheduling method which can reduce markedly space complexity and average computation time by combining the branch-and-bound method with CP/MISF; it allows us to solve very large scale problems with a few hundred tasks. Numerical examples are included to demonstrate the effectiveness of the proposed algorithms.

AB - Practical optimization/approximation algorithms are described for scheduling a set of partially ordered computational tasks onto a multiprocessor system so that the schedule length will be minimized. Since this problem belongs to the class of 'strong' NP-hard problems, it is not possible to construct pseudopolynomial time optimization algorithms or fully polynomial time approximation schemes unless P equals NP. A heuristic algorithm named CP/MISF (critical path/most immediate successors first) and an optimization/approximation algorithm named DF/IHS (depth-first/implicit heuristic search) are proposed. DF/IHS is an excellent scheduling method which can reduce markedly space complexity and average computation time by combining the branch-and-bound method with CP/MISF; it allows us to solve very large scale problems with a few hundred tasks. Numerical examples are included to demonstrate the effectiveness of the proposed algorithms.

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M3 - Article

AN - SCOPUS:0021529549

VL - C-33

SP - 1023

EP - 1029

JO - IEEE Transactions on Computers

JF - IEEE Transactions on Computers

SN - 0018-9340

IS - 11

ER -