What are some of the limitations / challenges of Adaptive Software Development (ASD)?

The Adaptive Software Development (ASD) culture is the result of efforts of Sam Bayer and Jim Highsmith in the field of rapid application development. The methodology aims at developing software that is capable of adapting continuously to the changes in the working environment. In ASD, in place of the waterfall approach, we have cycles of speculating, collaborating and learning. It is because of this dynamic cycle that the software is able to adapt to changing state of the requirements and learn through it. The cycle is very much tolerant to changes, driven by the risk, timeboxed and works in iterations.
Throughout the process the ASD life cycle remains focussed on the mission. Since adaptive software uses the information available from the environment for improving its working pattern, with the increasing complexities it becomes difficult for it to gather usable information. The effectiveness of the adaptive software development is reduced by the complexities of the environment. Today we expect more from the software and in such critical situations in which we never expected earlier. Thus complex environments pose a great challenge. There are three dimensions that contribute to this complexity:
> Increasing number of users: Now not only professionals, everyone uses software.
> Increasing number of systems: More number of systems means more number of interactions between them. Most of the system networks that we have now are heterogeneous. Maintaining homogeneous networks is easy.
> Increasing number of resources and goals: The most common trade off that programmers make is between time and space. Now there are several other things to worry about including security, bandwidth, money, quality, resolution and so on.

These three dimensions make it even hard for the designers to design a system. It is impossible to predict about these factors and therefore always right decisions can’t be made. This results in a product with a short lifetime. Every now and then upgrades will be required for modifying the software. Other factors related to complex environment that pose a challenge for adaptive software are:
> uncertainty
> hidden inputs
> non – deterministic
> unique
> continuity
> real world

Other things that put limitations on adaptive software development are following 4 myths:
> The traditional belief is that the specifications must be determined first. But this is not the case always. One specification can be taken at a time and refined in later stages. The aim should be combining several components together successfully and not developing a single app.
> People usually believe by maintenance that program code has degraded. The truth is that it remains the same while its environment changes. So maintenance involves evolution of the code to satisfy these changing needs. When programmers view this through a maintenance perspective, they tend to preserve the old program structure.
> It is undeniable that abstraction has an important role to play in the development process. But when we treat a process as a black box object we are actually ignoring the practical problem it faces of resource usage. In adaptive software development we take a new approach called open implementation. Here the modules have two interfaces – one for input/ output and the other checking performance. These two interfaces are perpendicular to each other. ADS also adds a feedback mechanism to this orthogonal interface system making it much better.
> While designing software we consider all the possible alternatives. The desired one is kept and the others are rejected. This means that once a requirement changes, we again have to see what alternatives are available and which one can be implemented. This might require changing all of the program structure. The best thing here to be done is programming the system such that it reconfigures itself.

How is Adaptive Software Development (ASD) different from Scrum? Part 2

Read the First Part (Adaptive Software Development being different from Scrum - Part 1)

For understanding the further differences between the two, it is important that we know what Agile Development is. The Agile manifest defines the agile methodology. There are 7 agile methodologies; namely XP, Crystal orange, Scrum, Adaptive Software Development, DSDM, Pragmatic programming and Feature – driven development. All these methods differ in their mechanisms and the parameters they take. All these methods have a different agile life cycle. For ASD, it depends on what techniques we are going to use. Generally speaking it doesn’t have a life cycle of its own. In contrast to this, scrum has an abstract lifecycle which packs certain activities in to its schedule.

However here we discuss differences based up on a lifecycle having some general phases.
- Project initiation: This step includes justification of the project and determining the requirements.
- Planning: Laying out an elaborate plan for development and leaving some gap for contingency actions. Scrum doesn’t have choice for including optional phases. It must work within predefined options, whereas the adaptive software development can have many options because it does not limits itself to few techniques.
- Elaboration of requirements: This stage is optional. The requirements are explained in great detail. Scrum does not implement this stage separately, but, it may be done in Adaptive Software development. Since the requirements are still in high level, they need to be broken down in to simpler specifications. The requirements are collated in to requirements document after classification. This document also contains use cases apart from the requirements.
- Architecture: Both scrum and ASD are based on agile principle of, design today and refactor tomorrow. Software developed using ASD can be modified to suit the changing environment just by adjusting their software capabilities and leaving the hardware unchanged. Software developed through scrum has to be modified through manual intervention and may even require to change hardware. A system architecture document is prepared in this phase.
- Release: The software is released to the customer. It has one timebox at least. Scrum can have many releases depending upon the development span of the project. Adaptive software usually delivers product in one go.

One of the important questions to be asked during project initiation phase is that whether to invest more or not? Not all methods answer this question. However addressing this question is an important part of the adaptive software development. Scrum doesn’t address this question explicitly. Next step is choosing the appropriate method. Scrum claims that it can be used for any project. Adaptive software development creates a list of all alternatives that can be used and chooses the best one.
The level of formality to be maintained in scrum is given by documents such as running code and backlog. In adaptive software development there are many too many choices to choose from. It makes use of vision statements for clearing out the confusion. Scrum defines a sprint goal which is a kind of timebox vision i.e., it follows one choice for some time and then can change if required.
Scrum avoids elaboration phase for speeding up the delivery. It uses product backlog maintained by the product owner.
Since adaptive software development may have an elaboration phase, it may also have a draft plan initially which may turn into a complete plan after determination of requirements. Scrum plans based on timeboxes.
Both methodologies help you work faster creating products with better quality. The agile customer too is an important role in the agile process. The customers are responsible for providing input during prototyping sessions. The organizing and controlling of user testing is the responsibility of the user. 

How is Adaptive Software Development (ASD) different from Scrum? Part 1

Adaptive software development and scrum both come under the overall heading of agile software development, but are two different beasts with differences between them. These are two different approaches with the same aim i.e., agile development. Below, we will write more on what differentiates the two.
It is necessary to know the differences between these two approaches since Scrum, as a part of agile software development is already a very famous methodology, whereas the adaptive software development is relatively new, but also a strong upcoming methodology ready to take the software development market by storm. Agile methods are always preferred over traditional development approaches to incorporate major factors such as increased levels of customer participation and satisfaction, project delivery flexibility, and acceptance of ongoing requirements or design changes at any level in the development process. This is the usual development scenario and that is why agile development methods are used mostly.  Most commonly used agile methods include:
-  Adaptive software development
- Scrum
- Feature driven development
- Extreme programming

Even though all these strategies aim at the same set of objectives (well almost), they do take somewhat different paths (having some items common, and yet others are different). It is important to know the differences between them. Otherwise how you are going to maintain agility in your development structure? Comparison between different agile methodologies, their common points and differences lets the managers choose the most appropriate agile method for their software characteristics.
There are many traditional techniques for drawing comparisons between 2 software development techniques. In this post, Scrum and ADS have been compared on basis of 2 areas, namely software construction and software requirements.
First difference between adaptive software development and the scrum approach is that in the former, there is no predefined technique to be followed. In scrum there are certain predefined techniques to be followed. On the other hand the focus of adaptive software development is on the end result rather on the steps. Adaptive software development methodology implements a particular technique only if it is required.
Since the last two years agile principles have encompassed methods such as extreme programming, feature driven development, adaptive software development and so on.  So far companies using scrum or adaptive software development have been able to deliver successful products. Scrum is described as a process for management and control used for cutting down the complexity. This is used by the organizations who want to deliver products faster. This approach to software development has been used on advanced development methods including software; it usually works well in the object – oriented development environment.
On the other hand adaptive software development is described as methodology for developing reliable and re – adaptive software. It is used by the organizations who want their products to function in a wide range of changing conditions. Software built with this approach are capable of reconfiguring themselves to better suit to the environment. It can be used under any kind of environment. Any technique can be applied here to make software as much flexible as possible. The owners are responsible for estimating backlog items in scrum. In adaptive software development it is mainly the task of the developers.
Scrum follows time-boxing method for speedy delivery. At the start of each timebox, a sprint planning meeting is held. A backlog that can be achieved is picked up by the team members and they decide how it can be achieved.
Scrum may have 1 to 4 teams with 5 – 9 members and adaptive software development may have even more number of teams dedicated to each phase of development process. Agile developers play a number of roles – analysing, estimating, designing, coding and testing. Even though the typing burden is less, there is a lot of stress because of the short frames. But you get to see your progress through user reviews and daily meetings.

Read next part  (Adaptive Software Development being different from Scrum - Part 2)

What is Adaptive Software Development (ASD)?

There are many a software development processes, with adherents and proponents for each one of them. Here we discuss about one of them i.e., ASD or Adaptive Software Development. This process is a result of Sam Bayer’s and Jim Highsmith’s efforts concerning RAD process i.e., rapid application development. ASD is based up on the principle that the development process must be continually adapted to the work at hand as a normal affair.
This development process is sometimes used as a replacement for the traditional waterfall approach. The steps in the waterfall model are replaced with repetitive sets of cycles of speculation, collaboration and learning. This cycle is quite dynamic in nature and allows us to maintain a continuous learning process. It also makes it easy to adapt to the project’s next state. An ASD life cycle is characterized by the following characteristics:
• Mission – focused
• Feature -  based
• Iterative
• Timeboxed
• Risk driven
• Tolerant to changes

Here by speculation we mean “paradox of planning”. Adaptive software development assumes that in the mission of a project, fault in certain aspects of it can be traced to all stakeholders’ mistakes. These mistakes are usually made while defining the requirements of the project. Efforts concerning the maintenance of work balance and environment and adapting to the changes in the environment (caused mainly due to requirements, technology, software vendors, stakeholders and so on) come under collaboration.
The learning cycle on the other side consists of many short iterations involving designing, building and testing. The aim of these iterations is to gather knowledge based up on small mistakes made and based up on false assumptions and then correcting them. This leads to great experience in the domain.
A lot of money and time goes into developing a piece of software, but it still proves to be brittle in some unexpected situations. Then how does adaptive software development makes it better? As the name suggests, ASD is focused up on development of such programs that are capable of readily adapting in the event of changes resulting from user requirements and development environment. It includes an explicit representation of the actions that the program can take and also the goals of the user. With this it becomes possible for the user to change the goals without rewriting the code. It is often used for producing what we call as the agent based applications.
We also have object - oriented programming and structured programming methodologies for developing software. With object – oriented approach the reorganization is easy with the changes because here we divide the functionality in to different classes. But still it requires the programmer to intervene to make some change. Therefore, this approach is kept confined to developing user – initiated event based applications. The structured programming was used to develop input/output based applications only since it cannot tolerate any changes in the specifications. The database managing programs are a typical example of this kind of applications.
There are several other methodologies for developing software. But they only provide solution for managing the changes rather dealing with them. It’s only adaptive software development that gives a real way of adapting to the change and dealing with it without having a programmer’s intervention. The best thing about adaptive software development is that it collects information about the environmental changes and uses it for improvement of the software. But today’s complex software and operating environments are making it less effective. Factors such as increasing number of users, systems, number of interactions, resources and goals etc. lead to complexity of the software. Now apart from time and space, programmers have to look out for money, security, resolution and so on.

What is Adaptive Software Development (ASD)? What are three phases of ASD?

Adpative Software Development (ASD) is a method for the creation and development of software systems. It focuses on rapid creation and evolution of software systems. ASD is a pat of rapid application development.

Adaptive software development life cycle is mission focused, feature based, iterative, time-boxed, risk driven, and change tolerant. In adaptive software development, the developer has a basic idea in mind and they g to work. The focus is in the computer code.

In ASD, there are no pre-planned steps. The software is made very quickly. New versions can come out very quickly as the development cycle is very short. The structure of adpative software development and rapid application development are similar, difference lies in the fact that:
- adaptive software development does not allow the time when the project is finished, rapid application development does.
- adaptive software development does not have a real end point whereas rapid applicatio development allows the end of project.

Adaptive Software Development life cycle comprises of three phases:
- Speculation
- Collaboration
- Learning

In speculation, user requirements are understood and an adaptive cycle planning is conducted. It depends on bug and user reports.
Effective collaboration with customer is very important. Communication, teamwork, individual creativity are a part of effective collaboration. The individual developers combine their portions of work.
Learning cycles are based on the short iterations with design, build and testing. ASD teams can learn through focus groups, formal technical reviews and postmortems.