DECENTRALIZED MULTIECHELON INVENTORY CONTROL

This paper considers a model for decentralized control of an inventory system consisting of 1 central warehouse and a number of retailers. The cost structure includes holding costs at both echelons and shortage costs proportional to the time until delivery at the retailers. We analyze a procedure for coordinated but still decentralized control of the system. The procedure is based on a simple approximation, in which the stochastic lead times perceived by the retailers are replaced by their correct averages. The approximation enables us to decompose the considered multiechelon inventory problem into a number of single echelon problems, 1 for each installation. The information about how a certain decision at the warehouse affects the retailers is conveyed through the marginal cost increase with respect to a change of the expected lead time. This information about the retailer costs is used as a shortage cost at the warehouse. We show that a coordination procedure based on this information can be used for finding near-optimal reorder points for the system and provide bounds for the approximation errors.     

Social Workers and Child Welfare

Correspondence to Dr Gunvor Andersson, Lund University, School of Social Work, Box 23, 22100 Lund, Sweden. Summary What problems do social workers at social services offices haveto face in their child welfare work? How do they handle theproblems, and how important is the relation between the socialworker and the child's parents? The research project includes189 child welfare cases with 0–3-year-old children inten local communities in Sweden. The article shows that thesocial work can be categorized into four different types ofwork, where the work done, as well as the relation between thesocial worker and the child's parents, differ. (1) The socialworker is mediating help and support and has a positive contactwith the child's parents. (2) The social worker is exercisingcontrol and authority and has a negative contact with the child'sparents. (3) The social worker is doing treatment-oriented workand has a personal involvement and a relation to the parentsthat is important for the family and not exchangeable. (4) Thesocial worker is solely engaged in investigatory work with norelation to the child's parents, rather a neutral contact. Inthe categorization the concepts contact and relation are differentiated.Only in the treatment-oriented category, encompassing aboutone-fifth of the children, can one speak of a relation. In allcategories there are elements of both help and control, butdifferent ways of handling this doubleness.