作者：Mike Shaw

许多首席执行官和首席信息官总是会在面对手机业务应用的开发成本时倍感震惊。

对于任何开发者来说，他们都必须提前了解并采取相应措施去管理自己的开发成本，应用工具包供应商5app首席技术官Tim King将在此与我们分享了一些经验：

mobile-application(from vincentit.com)

设计

大多数人都认可手机应用设计需要花费一定的时间——面对一种单一的目标设备也许需要两周稳定的工作时间，而如果应用更为复杂或者拥有更多不同的用户界面屏幕，那便需要花费更多时间。

设计师们需要在讨论中明确手机的预期用户体验，如果你着眼于跨平台应用，设计师便需要再使用特定的手机模式而更好地理解终端用户体验。

除此之外，如果你想要选择黑莓平台，你便需要更深入地了解触屏模式，并将其与操纵杆模式做比较——为每款简单的跨平台应用以及更复杂的版本多挪出一周的开发时间。

开发

这里伫立着许多不可动摇的事实。据Twitterific（游戏邦注：一个Twitter客户端，由The Iconfactory公司开发，可以免费使用，但每小时会有广告弹出）开发公司透露，这款应用花费了他们1500个小时的开发时间，而根据当前的美元汇率换算，这款应用的开发共花费了他们15万美元。一款有关巴拉克·奥巴马的官方应用的开发者也表示这款应用共花费了他25周的时间，但是如果让他重新制作，他可能会省掉大半的开发时间，从而只需5万美元的成本。

应用可以划分为一些类别：

简单的应用，所有的数据都保存于手机上，未与任何服务器发生交互作用，需要开发者投入2至4周的开发时间。

应用将从数据库中提取数据，并将其呈现在一个简单的列表上，不过这需要开发者多花费2倍的开发时间。

使用更复杂的服务器端与数据整合在一起，从而让应用可以离线运行，但是根据估算这类型应用的开发大约要花费12周的时间。

完整的企业自动化应用，整合了业务流程并包含了购物车和支付网关，这类型应用的开发需要开发者投入3至6个月的时间。

这些估算都只是针对于单一的目标设备而言，如Android手机或iPhone。尽管后端整合也是可行的，但是除非你使用的是混合方法或在浏览器中创造用户互动，否则便不存在任何可支持的代码。

这种方法非常适合于跨平台应用的开发，否则当你想要支持其它设备时你可能便需要支付两至三倍的成本。

测试

确保应用在需要进行更广泛的测试时不会崩溃——比起拥有各种后端服务器的应用来说，简单的应用总是能够更快速地完成QA测试。当开发者希望通过测试去确保自己的企业自动化应用是否可行时，他们便需要考虑到所有可能发生的情况，如哪里有信号哪里没信号，以及在哪里可以转变成无线连接等。

我们总是很难去控制这些数据载体的变化，即当设备的IP地址发生变化时，较低级别的协议所提供的的标准误差纠正（如TCP/IP）便不再有效。除此之外，新的IP地址一般也需要经历新的身份验证。

此外，开发者还需要考虑不同手机平台所存在的不同版本。如果企业应用将支持最初的iPhone和iPhone 3G，它们将分别运行于iOS 3.1.3和4.2.1版本上。而如果面向的是Android平台，企业应用则至少需要在2.2，2.3，3.x，4.0以及4.1版本上进行测试，因为这些版本之间也存在着较大的差别。

如果你的开发业务是面向于黑莓，你便需要面向5，6，7这三种版本的设备进行测试，更别说即将发行的黑莓10和Windows 8了。

在所有情况下，测试阶段将会占用开发者10%的开发时间，并且必须能够有效支持每一种OS版本。

成本

以下图表便是关于不同应用类别的开发成本的比较。基于不同情况，我们将选取开发阶段的一些中间值，并根据设计测试每小时的成本为35英镑以及开发者每日开销为300英镑进行估算。基于不同操作系统，测试成本等于10%的总成本再分别乘以5，8和11。

当开发跨平台应用时我便能够通过使用之前的后端代码而节省下2至3周的时间（当应用变得更加复杂时）。

cost(from mobile-ent.biz)

不过估算也只是估算，实际成本可能会多上两三倍，特别是当你未能妥善管理项目或不能有效地压缩应用范围时。

但是我们可以保守地估计，如果你使用传统的开发技巧去开发一款简单的单一平台应用，你将只需要花费1万英镑，而如果你开发的是跨平台企业应用，那么成本将不下10万英镑。

（本文为游戏邦/gamerboom.com编译，拒绝任何不保留版权的转载，如需转载请联系：游戏邦）

OPINION: How much should a mobile business app cost?

by Mike Shaw

Dr Tim King, CTO of 5app, offers some advice on how to keep app spending sensible.

Many chief execs and CIOs are shocked at the full cost of developing mobile business apps.

It’s better to understand in advance and take steps to manage the costs, so here Dr Tim King, chief technology officer of app toolkit vendor 5app (a finalist in the ME Awards 2012) offers some advice on the subject:

Design

Most would agree that the mobile app design process takes a considerable amount of time – perhaps two weeks solid work for a single target device, or more if the app is complex and has many different user interface screens.

The designer also needs to understand the expected user experience for the phone in question, so if you are looking at a cross-platform app, then the designer will need to have used the specific phone model at some point to better understand the end user experience.

In addition, if you want to include BlackBerry then you need to understand how the touch screen models work and compare them to the joystick controlled models – adding another week of development time for each simple, cross-platform app, and potentially more for complex versions.

Development

Here there are more hard facts. Twitterific took 1500 hours to create according to one of the developers, which at current US rates is $150,000 (￡95,000). The developer of the fairly simple official Barack Obama app says it took 25 weeks but could be done in half that if he had to do it again so that would be $50,000 or ￡32,000.

Apps can easily be split into a few categories:

A simple app, with all the data stored on the phone and no interaction with any server, might take between two and four weeks to develop.

On the next level, apps that extract data from a database and display it in a simple list can be expected to take double that time.

For more complex server-side integration with data being cached so it works offline, the estimated time this would take is around eight to 12 weeks.

A full-scale enterprise automation app, with integration to business processes and possibly including a shopping cart and payment gateway, will take anything from three to six months.

These estimates are for a single target device, i.e. Android phone or iPhone but not both. Although the back-end integration will be shareable, none of the code will be unless you use a hybrid approach and create most of the user interaction within a browser instance.

This is an attractive approach when considering cross-platform apps otherwise the cost doubles or triples depending on the extra devices that need to be supported.

Testing

Making sure the app doesn’t crash when in use requires extensive testing, so a simple app is considerably quicker to QA than one that interacts with back-end servers. When developers conduct tests to ensure they have a reliable enterprise automation app, they have to cover all scenarios where the phone has mobile data signal and then it drops, or it switches to wi-fi.

These data carrier transitions are tricky to handle, as the IP address of the device changes and thus the normal error correction offered by low level protocols, such as TCP/IP, isn’t useful. Additionally, a new IP address normally requires a new authentication step to be gone through.

Then there are the different versions of each mobile platform that need to be considered. If enterprises are going to support the original iPhone and iPhone 3G, then they run iOS 3.1.3 and 4.2.1 respectively. For Android, an enterprise will need to test at least 2.2, 2.3, 3.x, 4.0 and 4.1 as there are significant changes between them.

If a business wants to develop for BlackBerry, then they will need to test releases 5, 6 and 7 as devices with these versions are still being sold. That’s not to mention upcoming Blackberry 10 and Windows 8.

In all cases, the testing phase will start at 10% of the development time and will be that again for each OS version needing to be supported.

Costs

The below table provides some comparison for costs. In each case, it is assumed the median estimate for the development phase and an hourly rate of ￡35 for design test and a daily rate of ￡300 for developers. Testing is 10% of the cost multiplied by five, eight and 11 for each of the operating systems.

I have allowed for some savings when considering cross-platform apps due to the re-use of the back-end code, saving one, two and three weeks respectively as the apps get more complex.

These estimates are just that, of course, and real costs may end up more than double the above, especially if the project is poorly managed and/or the scope of the app has not been tied down.

But it’s safe to assume that using traditional development techniques to create a simple single-platform app will cost around ￡10K and a cross-platform enterprise app won’t come in under ￡100K.（source：mobile-ent.biz）