软件维护(Software-Maintenance)英文.ppt

SE, Maintenance, Hans van Vliet, ?2008 * Advantages of L-type departmentalization Clear accountability Development progress not hindered by unexpected maintenance requests Better acceptance test by maintenance department Higher QoS by maintenance department Higher productivity SE, Maintenance, Hans van Vliet, ?2008 * Disadvantages of L-type departmentalization Demotivation of maintenance personnel because of status differences Loss of system knowledge during system transfer Coordination costs Increased acceptance costs Duplication of communication channels with users SE, Maintenance, Hans van Vliet, ?2008 * Product-service continuum and maintenance SE, Maintenance, Hans van Vliet, ?2008 * Service gaps Expected service as perceived by provider differs from service expected by customer Service specification differs from expected service as perceived by provider Service delivery differs from specified services Communication does not match service delivery SE, Maintenance, Hans van Vliet, ?2008 * Gap model of service quality SE, Maintenance, Hans van Vliet, ?2008 * Maintenance control Configuration control: Identify, classify change requests Analyze change requests Implement changes Fits in with iterative enhancement model of maintenance (first analyze, then change) As opposed to quick-fix model (first patch, then update design and documentation, if time permits) SE, Maintenance, Hans van Vliet, ?2008 * Indicators of system decay Frequent failures Overly complex structure Running in emulation mode Very large components Excessive resource requirements Deficient documentation High personnel turnover Different technologies in one system SE, Maintenance, Hans van Vliet, ?2008 * SUMMARY most of maintenance is (inevitable) evolution Maintenance problems: Unstructured code Insufficient knowledge about system and domain Insufficient documentation Bad image of maintenance department Lehman’s 3rd law: a system that is used, will change References: SE, Mai