Software rewrite vs refactor

And i dont mean that in the general sense that anyone in software. You should rewrite when it would be easier to start from scratch than to refactor. One thing that is different from when joel wrote that blog post 14 years ago is that refactoring software is so much easier now. In extreme conditions, making each change in the software becomes a painful nightmare. When the rewrite is not using existing code at all, it is common to speak of a rewrite from scratch. In such situations, the dilemma refactor or rewrite may capture the attention of project stakeholders. And thats updating your language versions, compilers, and libraries. Rewrite vs refactor has always been a question every software faces at some point in time which could be because of many reasons.

Tagged with refactoring, softwareengineering, projectmanagement. Ui is the trickiest one to refactor, and its why i avoid giant frameworks that lock you in. If you get complete control over the ui then you can rewrite sections and slowly migrate things. Traditional approach is to start performing changes in a secured manner because it is not sure whats really going to happen when a data structure is changed or update a variable i. Deciding whether to rewrite or refactor an application can be tough. Before making a decision to as which path to take rewriting or refactoring, we weigh our options and go for the best. Code refactoring is used to improve code design to make it easier to understand and extend. To objectively decide on what is best for the software. One topic within this book addresses the rewrite or refactor question. Log in or sign up to leave a comment log in sign up. Are you confused by the rewrite vs refactor debate. Thus, refactoring is the preferred way to incrementally improve the system. Rewrite vs refactor dilemma a lot of developer have a tendency to suggest rewriting legacy code instead of refactoring.

It is safe to suppress a warning from this rule if the complexity cannot easily be reduced and the method is easy to understand, test, and maintain. It is slow paced, improves quality with small and constant improvement. Checklist of refactoring done right way the code should become cleaner. You can refactor much of the code without losing anything and without a lot of the risk. You may slowly adapt the product for new external conditions or make one revolutionary rewrite. The question internally may be, can we afford to allocate the time and resources needed to get to the heart of this problem and develop a new, comprehensive solution. This inevitability haunts programmers and decision makers since the early days of software industry and it is. Refactoring should be done as a series of small changes, each of which makes the existing code slightly better while still leaving the program in working order.

This column was published in ieee software, the pragmatic. Incremental refactoring goes a long way, along with the boy scout motto. Together, especially with the inclusion of refactoring these words are speaking about changing some existing software. Im not sure it has any meaning ouside that context. Refactor when the code is difficult to understand and the team is not sure of what it does. At that point the code will be easy to change and it will be a. He suggested that the question is not between refactoring and rewriting but it is between either. You have the resource time, talent and tools to undertake the rewrite. It puts its information about why people tend to want rewrites and why its not a good idea in a succinct bulleted format. Refactoring improves nonfunctional attributes of software. You could rewrite the entire application using a more modern framework or new language, but you would have to justify the budget and divert resources. Legacy code, that old piece of software no one wants to touch, no one knows who wrote it and everyones afraid to. Rewrite or refactor 10 questions to ask yourself before. In particular, the line between refactoring and rearchitecting or rewriting was being blurred, and refactoring was being used as a label for any activity where you go back and do.

Often times the refactoring can happen while people are designing what the rewritten version is going to look like. Application refactoring vs rewrite sergio serra medium. A code rewrite gives you the benefit of experience you know the weaknesses of the old system, the design flaws, current requirements and future road map. From our experience, we would say that if you can refactor, you probably should. This question usually arises after few years from the first version of the software release. The question i have is how should a business go about doing that kind of cost analysis on software and be. Potential advantages of refactoring may include improved code readability and reduced complexity. Refactor vs rewrite posted on april 25, 2016 april 25, 2016 by tushar sharma conversations such as oh, this is such a cluttered design, this software has high technical debt, and what a complex piece of code. Sometimes just adopting modern coding techniques has a great benefit. Highlighting the factors he considered when deciding if he should refactor or rewrite the codeunderconsideration. The ast is printable to reconstitute the source code, including its original formatting. And please spare me the excuses that you dont have the discipline to refactor, youre better than that.

Ideally theyd be some external consultancy that could come in and run the rule over the quality of the code and the costs involved to keep it running vs rewrite refactor replace it. With legacy code, rewrite vs refactor is a valuable but tricky question. Generally, there are three possible solutions when dealing with legacy software. Here is an event storming followup activity that visually shows how far we are from the target.

Youll see this over and over again as you read blog posts about rewriting vs refactoring software. And i dont mean that in the general sense that anyone in software must ponder the question. Recently i read the book knigge fur softwarearchitekten translates to something like etiquette manual for software architects from two wellknown german authors of software engineering textbooks. The question i have is how should a business go about doing that kind of cost analysis on software and be able to have confidence in that analysis. Refactor vs rewrite from scratch dilemma definitive answer.

And theyre in no position to complain thats exactly what a software rewrite would mean too. A rewrite in computer programming is the act or result of reimplementing a large portion of existing functionality without reuse of its source code or writing inscription. The audit should take a look at the existing code base to determine what underlying problems exist and assess whether theyre best solved via a rewrite or refactoring. Your heart says rewrite it, this code is beyond hope. Refactoring is intended to improve the design, structure, andor implementation of the software its nonfunctional attributes, while preserving the functionality of the software. The simplest and most effective formula to use for solving any code refactoring vs rewriting dilemma is. For what its worth, i answer this question for a living.

You can plan for it, design a system that will overcome the challenges and plan for the future. Lessons from 6 software rewrite stories herb caudill medium. I do think there is no universal correct answer to this. What should i consider whan debating a code refactor vs. Comparing the costs of your existing systems ongoing maintenance and the potential benefits that youd ripe if you rebuilt it from scratch, to the costs of a big rewrite. When everyone on the project is at wits end and people are finally past the shock of the notion of a writeoff, the rewrite. Nov 24, 2009 he suggested that the question is not between refactoring and rewriting but it is between either.

Code refactoring is the process of restructuring existing computer codechanging the factoringwithout changing its external behavior. Kodu iyilestirme ya da bastan yazma soz konusu oldugunda gelistiricilerin ilk aklina gelen bastan yazma. The do nots of testing melissa explores five traditional qa approaches, in particular, how to develop them to add more value to support modern development approaches. He suggested that even when a team decides to rewrite the. It will take time, it will be much effort, and it will certainly only work out if all team members want it to, because it requires that no new ugly code is written and that every component that is touched gets incrementally improved. What is refactoring and what is only modifying code. After all, i can think of few topics in software development that draw as much debate as this one. Whether or not to rewrite your software is a complex decision, often with wideranging impact on the business. Rewrite or refactor 10 questions to ask yourself before you decide. Replacing data structures and algorithms is somewhat of a border case. Its just that this approach is an actual game changer and not just more of the same.

On the other hand, you could refactor the application, but its hard to know where to start and it might take even longer to bring the application to an acceptable state. Writing understandable code will allow others to easily modify it. One of the great things about refactoring is that you get to pick how much of your time you allocate to cleaning up existing stuff and how much you allocate to responding to new market demands. Has this question ever come up from one of the engineers on your team. An effective strategy is crucial time spent rewriting the system is time lost from adding new features to grow the business. What successful conversion rewrite have you done of software you were involved with. On rearchitecting vs restructuring vs refactoring in his short bliki entry refactoring malapropism, martin fowler discusses about how sometimes the refactoring term is used when is not. History has taught us that re write from scratch could be strategically dangerous for the product and the company. Refactoring is adaptation, while full rewrite is revolution. Tips to identify if there indeed is a problem with the existing code. If your development team has reached the point of no return and exhausted all other options, here are 10 tips on how to go about rewriting your code. Refactoring vs rearchitecting vs redesign vs rewriting. To fix a violation of this rule, refactor the method to reduce its cyclomatic complexity.

Refactoring helps you understand other peoples code. Note that sometimes its often impossible to refactor applications. But if i were to derive their actual meaning i would say. In this post we want to expand a little on the topic of rewriting vs refactoring a. Benden haberler ve refactor vs rewrite konusu youtube. Refactoring would refer to reorganizing your projects code. If you have to deal with someone elses dirty code, try to refactor it first.

Refactoring is a great way to do this, a step at a time. Source code for the original application is lost, and recovery is more expensive than rewriting. Refactoring vs rearchitecting vs redesign vs rewriting in a comment on an earlier post jon eaves expressed concern that refactoring is being overused as a verb. A legacy code can be considered as any code that was written before today. Ive trod this path before in various incarnations and ill do it again today. In particular, the line between refactoring and rearchitecting or rewriting was being blurred, and refactoring was being used as a label for any activity where you go back and do things right the second time. You will improve it not only for yourself but also for those who use it after you. For instance, if the refactoring effort would involve months of retrofitting procedurallywritten oop code to proper oop before you could even start to refactor the code, then a rewrite is the better option because you have to change everything. To objectively decide on what is best for the software one should analyze on the following points. Rewrite vs refactor join anand on the 10th march at 8pm to learn the difference between refactoring and rewriting your code, regardless of the code youre working. You likely wont need to refactor small projects, but if your. The deciding difference here imo is the small steps. Rewrite when it is clear what the code does but it is difficult to understand.

The rewrite project is a refactoring tool for java source code. What you should consider is that a code rewrite is incredibly expensive and risky. Finally what is the top one or two thing you learned from being involved with the process. Apr 25, 2016 in extreme conditions, making each change in the software becomes a painful nightmare. Factors to consider if you should rewrite or refactor.

May 24, 2018 bu videoda en cok merak edilen konulardan biri olan refactor ve rewrite konusunu ele aldim. Lets say that you are unhappy with your projects code structure maybe. Refactoring is often used as the opposite of a rewrite. This should trigger more insightful discussions, and to the identification of the first migration steps. The refactor vs rewrite question why dont we just scrap all of it and start over. Here are my 10 questions to ask yourself to decide whether to rewrite, or to refactor.

If its somebody elses code, rewrite from scratch all software houses seems to think this way comment. Make sure youre accounting for these factors in your software rewrite or refactor decision. We at sloboda studio see refactoring as a viable option though we could in some instances rewrite the codes. Its easy to think that because it has been written before that it will take less time. Personally i dont think one approach is better than the other. It contains a custom abstract syntax tree ast supporting java 8 language features that encodes the structure and formatting of your source code. Developers and architects like to build things, so their initial impulse is often to flatten the place, lay some stronger foundations and build something impressive. What where the languages and framework involved in the process. Refactoring legacy code should be done as a step by step activity within a longer period of time. Refactoring is intended to improve the design, structure, andor implementation of the software, while preserving the functionality of the software. Refactoring is changing the internal structure of the code without modifying its external behavior. Sometimes it is worth it, but i think people tend to want to overuse rewriting. On re rearchitecting, restructuring, refactoring and. Understand that it will probably take longer than you think.

Most software projects run longer than they are expected to, and the same is true with rewrites. Software management, software strategy editorial note. Many times, it is brought up by one of your best engineers. If you must rewrite the rewrite will always take longer than you think. Rehost vs replatform vs refactor when to use which when migrating applications to cloud, it is important to consider business goals, application capacities, and costs of migration. All three options should always be considered when reaching that point in the software development life cycle, and this talk examines the costs and benefits for each. Why refactoring code is almost always better than rewriting it. Recently, ive read an article on infoq called refactor or rewrite. Before focusing on the differences, lets point out the obvious similarity. I would say there is a third category in the refactor vs rewrite space.

Mobile app rewriting vs app refactoring mobindustry. When you throw away working code, you are throwing away a huge number of hours of work including decisionmaking about fine details and edgecases which may not. The vast majority of the business rules encapsulated by the existing application no longer apply. Weve got this app, and we want to know if we should refactor it or rewrite it. After all, i can think of few topics in software development that draw as much debate as. In this post, im going simplify things for you and help you decide if you should rewrite, refactor, or do something else to improve the health of your software system. I will keep the word refactoring for the end, because this one has a quite specific meaning in the context of agility. If the code is indeed a mess, you dont necessarily have to rewrite everything all at once to make it better. We believe that a comprehensive audit is the first step in deciding between a refactor or rewrite.