The banking industry is one of the business units that need to be managed properly and yet still refers to the rules set by the regulator. At the end of the estuary of the banking business, both conventional and Islamic banks must perform well as a company, and the important thing in this industry is the management of capital adequacy ratio (CAR) in the risk sector of banking industry. Capital is a mean to finance income-producing assets and the protector of stability. From the point of view of efficiency and return, capital are part of bank funding sources that can be used directly to purchase assets and also to raise other funds. From the viewpoint of stability, the bank's capital act as a protector to absorb the shock of the loss of business and maintain solvency, to the benefits received by customers and other stakeholders. Capital Adequacy Ratio is one of the important concept in banking which measures the amount of a bank’s capital in relation to the amount of its risk weighted credit exposures. With this study the authors wanted to fill the void in the context of the present study is to see Islamic banking strategy in the management of the fulfillment of capital (CAR) not only from the internal side but also includes influences from the external side. The ability of banks to maintain liquidity affected the efficiency of the bank's risk management in creating a foundation in business activities as well as bank must choose the level of risk and profit ratios the best. The bank's risk can impact effect on operational costs and ultimately impact the Capital Adequacy Ratio (CAR) of a bank (Jasiene, M., 2012). Kweme (2003), noted the importance of capital adequacy for banking business activities. This means that banks will be able to absorb the liquidity risk in the market, if it has a capital adequacy ratio (CAR). To encourage the prudent management of the risks associated with the structure of the balance sheet, the authorities in most countries introduce specific capital adequacy requirements. At the end of year 1980, Basel Committee on Banking Supervision lead in developing capital adequacy standards-based risks that will lead to international convergence regulatory oversight governing the capital adequacy of international banks are active, with the aim to strengthen the health and stability of the banking system, which then developed further by the Islamic Financial Standards Board (IFSB), which in turn set standards of capital adequacy for Islamic banks is not lower than 8%.
In 2004, Basel II proposes a tightening of the rules of CAR. Meanwhile, Basel III is no improvement associated with increasing riskweighted capital requirements (divided into Tier 1 and Tier 2) and nonrisk-weighted leverage ratio. Polat and Al-Khalaf (2014) in his research to analyze the relationship specific variables banks, including CAR (dependent variable), profitability (ROA), non-performing loan (NPL), loan-to-deposit (LTD), leverage (LEV), the dividend payout ratio (DPO), loans (LOA), bank size (Size). This indicates that the ability to maintain the CAR is very important for the health of a bank. Interesting study also done by Siti Rochmah et al (2011) regarding the financial performance of Islamic banks and conventional banks. Now, the conditions are different. The financial performance of Islamic banks are not better than commercial banks. This is reflected in the measurement of the CAR, ROA, ROA, and LDR or FDR as follows:
From several studies including that conducted by Erico and Partners Farahbaksh (1998) states that the rules of economic authority for sharia bank can basically use the same size with the bank, although in some cases the management of Islamic banks and conventional is similar.
Said (2012) conducted a study on how the application of the system of Islamic banking ranging from the establishment of the beginning of the establishment of the Dubai Islamic Bank in the United Arab Emirates, then continues in Jidda, Saudi Arabia, Egypt, Sudan, Kuwait, Bahrain and other countries. The need to put forward that are relevant to my research is put forward a study conducted in Indonesia are carried out by Umar, Majid and Rulindo during 2002 to 2004 at 21 private banks with DEA method. With a sample consisting of two Islamic banks and conventional banks remaining. Likewise research done by Saifullah, on 2004-2008 found that Islamic banks are better in business development, profitability, liquidity and solvency compared with conventional banks. This was stated in the Journal of Literature Review, that on variety of studies both conventional banks and Islamic banks is mainly related to the bank's financial performance, especially in terms of efficiency between Islamic banks, including a variety of discourse, controversy and inconsistency of various studies. In this study the approach to measure efficiency was still simple. The purpose of this paper is to present conceptual framework to see what factors are affecting the Capital Adequacy Ratio, which include internal factors which consists of some financial ratios, then Size banks and external factors, namely inflation rate. Many studies, linking the effect of achieving the CAR management, attributed to internal factors and financial ratios. But, not many who measure CAR, from internal and external at the same time, the macroeconomic factors in this study is the inflation rate. Lia Amaliawati and Lasmanah(2014) addressed the issue of Capital Adequacy Ratio and some other financial ratio bu there, CAR is not as dependent variables but parallel with the other variables acts an antecedent and also was associated with bank management efficiency. Many studies, linking the effect of achieving the CAR management, associated with its financial ratios. But, from the reference study, there has been no or not much that incorporate elements of management initiatives, namely the management of measurement of the size of CAR in the bank. In one article(Cohen, 2014), the author fill the research gap on this side. Also Schaffer(2011) delivered on banking studies which incorporate at least the macro element in the management of his CAR, has been a differentiator with previous studies, the researchers conducted answers to the current debate between the management of CAR. Research conducted Dreca Nada (2013) and Ahmet and Hasan Buyuk salvarci Abdioglu (2011) convey the determinant factors affecting capital adequacy / CAR, but seen from internal factors. The dynamics of the market risk in theIndonesia banking structure requires to be able to manage capital adequacy ratio (CAR) which is able to adapt to external shocks. As also stated by Nnanna (2003), a common indicator of macro factors developed by the IMF in assessing the health of the Bank with the acronym CAMELS which include Capital (adequacy), Assets, Quality, Management, Earnings, Liquidity, and Sensitivity to market risks. Research on the CAR, especially in Islamic banking has been done by several researchers, although not much compared to conventional banks, but in this study the researchers wanted to know CAR associated with the external dynamics that inflation rate. Empirical studies on the determinants of banking Saudi Arabia against CAR (Polat and Al-khalaf, 2014) as well as the idea to include macro policies factor into it (Cohen and Scatigna, 2014), an interesting topic for research on Islamic Banking in Indonesia. Because not much research, especially for Islamic banking which combines internal factor by factors external / macro against Capital Adequacy. Some studies usually do so partially, this is where the researchers want to find a gap theory that has never been done by other researchers. Many studies, linking the effect of achieving the CAR management of both conventional and Islamic banking more just through its financial ratios or internal factors. But there has been no or perhaps rare that CAR management for Islamic banks that combined with external factors. The purpose of this study is to propose a more comprehensive research model to complete some previous research that can be developed more fully and comprehensively to determine the determinant factors on the capital adequacy of Islamic banks.