Centralized Management with Delegated Administration
Often Medium/large organizations composed of several geographically dispersed units, such as CNR, use distributed network services which guarantee maximum flexibility for the single operating units but bear the management and maintenance costs (HW, SW, and human resources) of several servers.
In this context the migration from a distributed to a centralized model would reduce the costs considerably but on the other hand would limit the autonomy of outlying units.
An effective solution may be a hybrid organizational model: partly centralized and partly distributed. The idea is to concentrate the systems management operations in a smaller number of servers (to be evaluated based on an analysis of the network topology, traffic, etc.) keeping the entire distribution of administrative tasks among the organization's operating units by means of delegating by web. We have called this approach Centralized Management With Delegated Administration , .
Designing systems based on the CMDA model
In order to decide which systems to automate and in what way, we can offer several observations:
Based on these considerations the figure below shows the relationships between the frequency of administrative actions and the level of technical skill required. The lower part of the triangle includes very frequent operations requiring a low level of technical knowledge, while toward the apex of the triangle the knowledge level increases and the frequency of the operations decreases.
The mechanism of Delegated Administration, entailing complete distribution of the load between several operators, has proved to be effective for optimizing the use of resources as well as holding down costs.
Based on this model the Integrated Network Services Manager system was designed and developed for integrated management of Electronic Mail, Mailing List, and DNS services , .
 Francesco Gennai, Laura Abba, Marina Buzzi. Exploration of the design of a complex e-mail system. Journal of Computer Resource Management - Computer Measurement Group Inc. Issue: One Hundred, Fall 2000, pp. 14-26 e Conferenze CMG UK 2001, 1-3 Maggio 2001, Edinburgo e CMG Italia 2000, 8-9 Giugno 2000, Milano.
 Francesco Gennai, Marina Buzzi, Laura Abba. Delegated Administration of Network Services. Poster alla Conferenza SANE 2002, 27-31 May, Maastricht (NL).