Applying systems thinking to analyze and learn from events

Major accidents keep occurring that seem preventable and that have similar systemic causes. Too often, we fail to learn from the past and make inadequate changes in response to losses. Examining the assumptions and paradigms underlying safety engineering may help identify the problem. The assumptions questioned in this paper involve four different areas: definitions of safety and its relationship to reliability, accident causality models, retrospective vs. prospective analysis, and operator error. Alternatives based on systems thinking are proposed.     

Is risk analysis a useful tool for improving process safety?

To improve safety one has to know where risks are. For determining risks, hazards have to be identified and representative accident scenarios defined. This needs effort and technique. Man is quite limited in foresight without having experience and lessons from the past. For knowing the risk of an incidental, undesired event both its severity and probability has to be estimated. Then ways to reduce risk become clear. In a process plant risks are many and it is not possible to remove them all. One has to attribute priorities. Intuitive and qualitative methods can do much, but plant complexity may be large and communication on risk may become difficult without formal methodology. Quantitative risk analysis offers much, but has its weaknesses and drawbacks. The required effort is considerable, specialists are needed, and variability in answers is large. Yet, a model built to go along with the life of an installation and updated periodically may be very useful. This paper presents an overview of the demand, problems encountered, possible remedies, and an outlook on useful improvement and extension of risk analysis methodology, including decision making.     

Incorporating sustainable development concerns into an urban regeneration project: how politics can defeat procedures

It is often thought that new procedural arrangements can help embed sustainable development as a policy goal into policy practice. This is the hope of tools such as environmental assessment, sustainability audits and sustainability indicators. Using a case study of urban regeneration in the London Borough of Southwark, this paper critically examines these claims. It shows how sustainable development was sidelined as a policy goal during the evaluation of the Master Plan for the area, the appraisal of individual projects for funding under the Single Regeneration Budget and the development of two local sustainability indicator projects. In each case the local political circumstances were key factors in shaping policy practice and outcomes. This leads to a re-evaluation of such procedural policy tools, emphasizing the importance of local governance contexts.     

实践中的能源管理：社区行动起来保护气候

地方环境举措国际理事会 (ICLEI)城市气候保护运动与地方政府一起工作，采用综合的和战略的能源管理手段减少温室气体排放 .对参加气候保护运动的 43个国家的 386个城市地方政府的抽样调查表明，实质性的行动已经改善了地方的能源管理并且减少了温室气体（ GHG）排放 .     

Dynamic Risk Perception in Two Communities: Risk Events and Changes in Perceived Risk

This paper examines the relationship between perceived risk and hazard events in two communities in terms of the perception and acceptability of risk. One community experienced an acute risk event comprised of a fire at a chemical plant that resulted in a large-scale evacuation (an acute hazard). The other community was involved in a seven-year controversy over the siting of a hazardous waste incinerator (a chronic risk). While the results are broadly consistent with a learning model of perceived risk, the support is more limited than envisioned; hence, the static forces of risk perception are stronger than anticipated.     

Prenatal diagnosis of trisomy 20 by chorionic villus sampling (CVS): a case report with long-term outcome

A case of prenatally diagnosed non-mosaic trisomy 20 in cells cultured from a chorionic villus sample (CVS)is presented. The term placental karyotype was also non-mosaic trisomy 20. The karyotype of thenewborn was 46,XY/47,XY,+20 in foreskin cultures and in a second skin culture; blood lymphocyte culture was 46,XY. Aside from diffuse, hypopigmentary swirls along the lines of Blaschko observed on hisextremities and trunk, referred to as hypomelanosis of Ito, the patient is clinically normal at 8¾ years ofage. In addition, he is one of the oldest reported cases of mosaic trisomy 20 confirmed after birth forwhich the clinical outcome has been monitored. This case demonstrates that these trisomy 20 findings are compatible with normal psychomotor development and phenotype. Copyright © 2001 John Wiley & Sons, Ltd.