Product redesign is hardly a straightforward process, especially for complex products. The existence of intricate interrelationships between different components of product design architecture makes it more susceptible to change propagation phenomenon. In this case, redesign risk is not easy to predict since the change effects are being propagated to other components from the initiating change component. Because of this condition, choosing the right initiating change component is essential to control redesign process risks, apart from being able to successfully satisfy the product requirements. With this notion, this paper proposes a method that systematically ranks all components of an existing product design based on their estimated redesign risk. By having this information, designers can make a better redesign planning. The demonstration of this method is presented through an example aircraft redesign case study.

Change Ranking of Product Subsystems (CROPS) is a computer program that is designed to act as a decision-making aid for designers during early stages of their product redesign process. It generates a ranking of all subsystems within the existing product design architecture based on their estimated redesign risk. This information assists designers in selecting the right existing subsystems to be initially changed to satisfy the driving requirements, which have to be quickly decided. In this program, evaluation of redesign risk captures both direct and indirect change effects that potentially result from the modification of each subsystem. Designers are provided with a relative reference as to how risky and extensive it is to change one subsystem over the others, which can be useful when they have options to pick between several subsystems to modify for the same redesign requirement.

Redesigning an aircraft is hardly a straightforward task. Due to its high susceptibility to change effects propagation, it becomes very important to select the right initiating change components to minimize redesign development risks. With realization that there are often several different ways to redesign an existing aircraft for satisfying similar requirements, designers might require assistance in selecting suitable initiating change components in their redesign plan. A methodology that systematically ranks the subsystems of the chosen baseline design according to their estimated redesign risk is proposed here. It is strongly believed that making this information available to designers during the early redesign stages will help them to make a better redesign plan. KEY WORDS: subsystems ranking, aircraft redesign, redesign plan ABSTRAK: Reka semula sesebuah pesawat udara bukanlah satu tugas yang jelas dan mudah. Memandangkan ia mudah rentan terhadap perubahan rambatan, amatlah penting untuk memilih penukaran komponen yang sesuai pada peringkat awal untuk mengurangkan masalah pembangunan reka semula. Menyedari bahawa terdapat beberapa cara untuk mereka semula pesawat udara yang sedia ada, demi memperolehi keputusan keperluan yang serupa dan memberansangkan, pereka wajar mendapatkan bantuan dari segi penukaran komponen yang sesuai pada peringkat awal pembangunan reka semula yang menepati rangka pelan reka bentuk mereka. Metodologi yang sistematik meletakkan subsistem dasar reka bentuk yang dipilih, berdasarkan anggaran risiko reka bentuk semula dicadangkan di dalam kertas kerja ini. Adalah diyakini bahawa dengan memperolehi informasi ini di peringkat permulaan reka bentuk, ia dapat menolong pereka merangka pelan reka cipta yang lebih baik.