In operations management and industrial engineering, production flow analysis refers to methods which share the following characteristics:
Contents
- Classification of machines
- Technological cycles information control
- Generating a binary product-machines matrix (1 if a given product requires processing in a given machine, 0 otherwise)
Methods differ on how they group together machines with products. These play an important role in designing manufacturing cells.
Rank Order Clustering
Given a binary product-machines n-by-m matrix
- For each row i compute the number
∑ p = 1 m b i p ∗ 2 m − p - Order rows according to descending numbers previously computed
- For each column p compute the number
∑ i = 1 n b i p ∗ 2 n − i - Order columns according to descending numbers previously computed
- If on steps 2 and 4 no reordering happened go to step 6, otherwise go to step 1
- Stop
Similarity coefficients
Given a binary product-machines n-by-m matrix, the algorithm proceeds by the following steps:
- Compute the similarity coefficient
s i j = n i j / ( n i j + u ) for all withn i j - Group together in cell k the tuple (i*,j*) with higher similarity coefficient, with k being the algorithm iteration index
- Remove row i* and column j* from the original binary matrix and substitute for the row and column of the cell k,
s r k = m a x ( s r i ∗ , s r j ∗ ) - Go to step 2, iteration index k raised by one
Unless this procedure is stopped the algorithm eventually will put all machines in one single group.
References
Production flow analysis Wikipedia(Text) CC BY-SA