Answers:

a. As an IS designer who is assigned to make a new accounting system, the very first organizational factor that I would greatly consider is the culture and environment of the company, and the scope of the business. This talks about the technical details of the business, its organizational structure, selling and distribution processes, the type of cost information the company is running, its manufacturing procedures, and company reports like financial reports. It is important factor to consider so that I will know what accounting tasks the software would ideally perform and to be able to distinguish the purpose of the accounting package. The next factor is the access and portability, or the server that is suitable for the company. Another factor to consider in making a new accounting system design and selection is the system cost. The budget of the company should be put into contemplation. How much they are willing to spend for personalizing a system that would of course determine product cost, like a system that would use standard costing, actual costing, or marginal costing. These things are to be considered as well because it is important to make the accounts in the system specified to be convenient for financial analysis. Another organizational factor is the system users, and the ones who can have an access control to certain information. An accounting system has to be controlled properly to minimize mistakes and fraudulent activities. Also I will take into account the knowledge and technical capability of the employee who will use the system. So, it should be user-friendly. Also, an organizational factor I would like to consider is the strategy that connives with basis of accounting that the company uses; like cash or accrual basis for accounting. 

b. Business Process Redesign or Business Process Reengineering is a complete overhaul or refurbishment of a company's business process to make it more efficient. The following are the changes that urges the company to call for a BPR:  

1. Changing technology. These changes requires the company to have a new infrastructure to remain competitive. A business may be compelled and obligated to abandon its current processes and adopt new ones just to endure and continue being up to date of its peers and competitors, as new technology appears the globalization of business. Generation tends to become more techonogically advanced, and it calls for businesses to meet its demands. 
2. Demographic Shifts. This shift has something to do with the change in the growth of population in terms of average age, dependency ratio, life expectancy, family structures, birth rates, labor force participation rates. As demographics change, product life cycles shorten, and the role of technology accelerates, decisions about when and how to integrate a target become more complex. This situation will lead the company organization to think on how to cope with the environmental change. 
3. Economic Fluctuations. A business will need a call for BPR if it is greatly affected by economic fluctuations. The instabilities in the level of national income of a country represents the growth or contraction of the economy. And a business cycle is determined as the  pattern of economic fluctuations describing economic fluctuations in a market economy. A business needs to strive in order to deal with a growing economy or a contracting economy. This is where BPR is called to be considered because an economic climate affects business in ways of unemployment, changing levels of consumer income, interest rates, and tax rates. 
4. Dynamic Conditions like change in government policies. The government can pass laws and regulations that would greatly affect business industries. Governments have the capacity to make broad changes to monetary and fiscal policy, including raising or lowering interest rates, which has a huge impact on business. Governments can create subsidies, taxing the public and giving the money to an industry, or tariffs, adding taxes to foreign products to lift prices and make domestic products more appealing. Higher taxes, fees, and greater regulations can stymie businesses or entire industries. This calls for BPR if necessary.  

Step-by-step explanation

https://en.wikipedia.org/wiki/Business_process_re-engineering

https://www.researchgate.net/publication/323677148_Impact_of_Business_Environment_Change_On_Entrepreneurial_Behavior_and_Business_Process_Reengineering_BPR

https://www.bbc.co.uk/bitesize/guides/zjjnnrd/revision/1

https://yourbusiness.azcentral.com/general-journal-vs-general-ledger-12566.html

https://learn.financestrategists.com/explanation/cost-accounting/essential-factors-to-be-considered-for-designing-a-cost-accounting-system/

https://www.sbsgroup.com.sg/blog/7-factors-to-consider-when-choosing-accounting-software-for-small-business/

Here are some links of the articles that you can further read for more information :)