AUTOSAR - Advantages and Disadvantages

Prerequisites: ECU  AUTOSAR Overview

This article explains you the advantages and disadvantages of AUTOSAR

Any company would only switch or make changes in its process only if it gets benefit in time (which will result in  time to market or delivery and market control ), quality (Which will increase goodwill of the company) or money (increases money spent which in turn increases profit). So below the pros and cons of AUTOSAR are given which will finally boil down to impact n above mentioned 3 factors. These points will make you understand why AUTOSAR has become viral now in automotive industry.

Advantages of AUTOSAR:

1) Standardization of specification exchange formats: 

        Each OEM company previously had their own customized formats of providing requirement and specification to its tier1 company. So the tier 1 company has to invest some time in understanding the format and procedure or requirement handling. If a company had requirements from 100 manufacturers then there were 100 different formats in which requirements were given. But after AUTOSAR, the formats and content of specifications are standardized. By doing this the tier companies need to be familier with only standard format and reduces the time and hence improved productivity.

2) Standardization of Basic software: 

        The software present in an ECU can be divided into two major categories. One being the support software or the infrastructure and the second being the application software which implements the actual automotive functionality of value to the user. For example the drivers of hardware modules are the software which doesn’t give any user value by itself. But a software module which controls the headlight operation or injections etc have a application which is useful to the user and implements the feature for which the customer pays. So the infrastructure software which doesn’t have a standalone value is called as a Basic software whereas the software which implements a automotive function or feature is called an application software. The basic software on its own doesn’t implement any automotive feature so as a user perspective is of no value. But without basic software, the application software can’t work.  So in a way the time and money invested in the  design and development  of basic software  is a total waste.

AUTOSAR structure (Basic)

              AUTOSAR standardizes this BASIC software in order to reduce the time and money to be spend on BSW development. AUTOSAR defines the HDL (High level design) and structure of BSW so that only LLD (Low level design) Needs to be taken care by the company to have a standard BSW and concentrate its major focus on development of application software and earn good profit.

3) Layered architecture of Basic Software (BSW):  

            Suppose if the micro-controllers availability and manufacture is stopped or if the new functions implemented are overloading the existing controllers then the need for changing the micro-controllers arises. But if the underlying hardware is changed then entire basic software needed to be changed as entire BSW was previously designed based on hardware. But AUTOSAR has layered architecture of BSW as shown in below diagram. The layer MCAL abstracts the underlying micro-controller specifics from its above layers and ECU-AL abstracts the underlying ECU specifics from its above layers.  So if the micro-controller needs to be changed then there is no need to re-design and develop entire BSW but only the MCAL layer. So the effort and time and money which was needed to be invested in upper layers like ECUAL or service layers is saved.

AUTOSAR Layered Architecture

4) Software sharing between companies:

              Previously since each company had their own software architecture, the software modules from different suppliers could not be combined and put on a single ECU. So the entire software for a ECU needed to be developed completely by a single supplier. But AUTOSAR is a standard architecture and has made each software module as independent as possible. Due to this its possible to take multiple software components developed by multiple AUTOSAR following suppliers, and integrate them together into a single ECU. Due to this the manufacturers or OEMs has the option of selecting the best of software components from multiple suppliers and can integrate them in a single ECU and this improves the quality of the automotive systems a lot. 

5) Software Component Re-Usability:

              Previously, the software components were written and were dependent on underlying hardware and hence each software specific to its ECU. But AUTOSAR has made software components independent. When you learn AUTOSAR in further articles you will realize that software components in AUTOSAR are completely independent of hardware and also need not know from where is it getting its inputs and dependency of other modules on it. So a software component can be re-used in any ECU again and again and hence saves a lot of money. 

6) Standardization of Interfaces:

            When a small innovation need to be implemented at a reasonable effort, it was not possible as the software module implementation had to be implementation of the innovation and the redundant implementation to make the software module to adapt to the OEM specific environment. When I say OEM specific environment I mean that the interfaces which it takes needs to be same as it is in the existing software, the attributes of software implemented newly must be made to adjust to existing infrastructure. But with AUTOSAR, the interfaces are standardized which makes implementation of new small innovations as only implementing the algorithm. The architecture and integration process automatically makes sure that new module is fit in infrastructure. In simple words if a software component is implemented as per AUTOSAR guidelines and rules, then no effort or separate implementation is needed to make the software adapt to AUTOSAR infrastructure hence saving of time and money.

Disadvantages of AUTOSAR:

            AUTOSAR has no disadvantage but two negative point to classical suppliers due to introduction of AUTOSAR are mentioned below. Note that both disadvantages are with business perspective: 

1) Software sharing is a disadvantage to ECU suppliers:

            Before AUTOSAR was developed, The suppliers who manufactured the ECU used to develop entire software for the OEM. But since advent of AUTOSAR, software sharing is possible. It means the OEMs can take the software modules from multiple suppliers and integrate them on the ECU This means that when OEM takes a part of software from other supliers, then its a loss for the supplier who used to provide entire software before. So even though AUTOSAR is a plus point for OEM, it became a negative point to the supplier.

2) Initial investment cost for changing the architecture:

           This is not a disadvantage in reality. When AUTOSAR was developed and the companies adopted AUTOSAR, it doesn't happen overnight.  A lot of money and effort has to be invested in learning the new architecture, migrating the existing software implementation to AUTOSAR compliant software etc. So this is a investment from companies can be considered as a con. But once this phase is over, AUTOSAR compensates the loss and starts giving the profit very soon.

Author - Shyam Bhat