Organizations replace their legacy systems for technical, economic, and operational reasons. Replacement is a risky proposition, as high levels of technical and social inertia make these systems hard to withdraw. Failure to fully replace systems results in complex system architectures involving manifold hidden dependencies that carry technical debt. To understand how a process for replacing a complex legacy system unfolds and accumulates technical debt, we conducted an explanatory case study at a local manufacturing site that had struggled to replace its mission-critical legacy systems as part of the larger global company’s commercial-off-the-shelf (COTS) system implementation. We approach the replacement as a sociotechnical change and leverage the punctuated sociotechnical information system change model in combination with the design-moves framework to analyze how the site balanced creating digital options, countering social inertia, and managing (architectural) technical debt. The findings generalize to a two-level (local/global) system-dynamics model delineating how replacing a deeply entrenched mission-critical system generates positive and negative feedback loops within and between social and technical changes at local and global levels. The loops, unless addressed, accrue technical debt that hinders legacy system discontinuance and gradually locks the organization into a debt-constrained state. The model helps managers anticipate challenges that accompany replacing highly entrenched systems and formulate effective strategies to address them.

中文翻译：

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陷入技术债务：遗留系统更换的社会技术分析

出于技术、经济和运营方面的原因，组织会更换其遗留系统。更换是一个冒险的提议，因为高度的技术和社会惰性使这些系统难以退出。无法完全替换系统会导致复杂的系统架构，涉及带有技术债务的多种隐藏依赖项。为了解更换复杂遗留系统的过程如何展开并积累技术债务，我们在一家当地制造工厂进行了解释性案例研究，该工厂一直在努力更换其关键任务遗留系统，作为更大的全球公司商业关闭的一部分货架（COTS）系统实施。我们将替换视为一种社会技术变革，并利用标点符号社会技术信息系统变革模型结合设计移动框架来分析网站如何平衡创建数字选项、对抗社会惯性和管理（架构）技术债务。研究结果概括为一个两级（本地/全球）系统动力学模型，描述了替换一个根深蒂固的关键任务系统如何在本地和全球层面的社会和技术变化内部和之间产生积极和消极的反馈循环。除非得到解决，否则这些循环会累积技术债务，从而阻碍遗留系统的停用，并逐渐将组织锁定在债务受限的状态。