Overview IPF Property Management and Software group offer a range of services based around an extensive software suite. This includes hand held surveying software developed on Psion Workabout systems. One of these needed updating and moving to the Microsoft Pocket PC system. Village Software implemented the updated specification to run on Pocket PC's importing and exporting data in the flexible XML format. Village's testing oriented approach allowed a robust and complex application to be developed within the limited Pocket PC environment. By offering a fixed price contract Village allowed IPF to contain the financial risk of moving to a new technology. 
Return on Investment The Pocket Survey system is a replacement for an existing system and allows the considerable experience IPF has gained in Public Sector surveying to be contained into an updated platform. By choosing a leading platform and using a series of adaptable components a maintainable piece of software has been developed that can adapt in a fast moving technology environment. Components are used that are adaptable to changes in communication and handheld technologies. Use of XML as a communication medium will allow data to be passed back and forth to servers using off the shelf communication components. The business rules of the application are carefully separated out from the visual components and separately tested. This gives a robust platform that can be updated with confidence, as technology on hand held devices evolves rapidly. Company Background The Institute of Public Finance (IPF) (www.ipf.co.uk) is the commercial arm of CIPFA the public sector accounting institution. Situation IPF has an extensive suite of applications covering the range of property surveying undertaken in the public sector. The existing software running on Psion Workabout systems was ageing and a substantial rewrite was required to allow the resurveying of properties. It was decided that instead of evolving the Workabout software the application would be rewritten on a new platform, The Microsoft Pocket PC platform was chosen. IPF has its own software development team however this team was fully occupied on developments on the server side of the applications portfolio. They therefore needed a partner with good development techniques to work with this new platform. Solution Village was engaged to design and develop a new solution to IPF's functional specification. Village agreed to absorb the costs of adapting its development methodology to the Pocket PC 2002 platform. 
Technology Microsoft Pocket PC technology is a development of their Windows CE operating system. Development on the machine is similar to Windows PC based development. Microsoft produce a variant on Visual Basic called Embedded Visual Basic eVB for such developments. eVB has a number of limitations and flaws. It seemed likely that eVB will be replaced by Microsoft's Object Oriented VB.Net Compact Framework still under development when this project was produced. In order to ensure a robust design Village designers split the application into three layers. The database is supported in the Pocket PC version of SQL Server. The main business rules are contained in a series of Object like components in eVB. These simulate the programming structure for objects not available in eVB but expected in VB.Net. The forms that the user sees were build in eVB but were build stateless so that they are entirely depended on the middle layer objects for business rules. 
The objects in the middle layer of the system containing the business rules are quality checked by 140 automated tests to ensure ongoing integrity. The technology included a number of technical challenges due to limitations and bugs in the development environment. This absorbed an unexpectedly large time. General Conclusions Developing applications on Pocket PC platforms offers new opportunities to increase the efficiency of data collection. While technologies such as Embedded Visual Basic allow Windows programmers to develop such applications this still remains a specialist field due partly to the immaturity of the development environments. A simple eVB application might cost £5,000 to develop. A more complex application such as this Pocket Survey might cost £30,000. |
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Mar 2010
