Final answer:
An engineer can cease to act for a client due to personal, ethical, financial, or legal reasons. Ethical reasons are significant as codes of ethics by professional bodies like IEEE-CS set standards for protecting human life, privacy, and the environment. Engineers must consider scientific, ethical, economic, and legal aspects when facing large-scale problems.
Step-by-step explanation:
An engineer can cease to act for a client on various grounds, which can include personal reasons, ethical reasons, financial reasons, and legal reasons. Ethical reasons are particularly important as engineers are bound by codes of conduct set by professional organizations, which dictate that they must operate in ways that do not diminish the quality of human life, breach privacy, or harm the environment. Ethical considerations can involve large-scale problems where engineers should focus on not only scientific aspects but also ethical, economic, and legal aspects.
Examples of such instances when an engineer might have to cease working with a client include a conflict of interest, the client demanding actions contrary to the public interest, failure in payment of agreed fees, or a legal order prohibiting continued work. Each of these reasons would present a scenario where it might be necessary, or indeed compulsory, for an engineer to stop acting on behalf of a client. A professional engineer must take into account all these aspects to uphold their ethical obligations as per the guidelines of professional entities like the Institute of Electrical and Electronic Engineers Computer Society (IEEE-CS).